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-An Exploration in Niello-
jloose.com
-An Exploration in Niello-
Cup for the Moon. Silver, niello, garnet. J.Loose, 1993.
An Exploration in Niello
Submitted as partial fulfillment toward the degree of Bachelor of Fine Arts
at the Portland School of Art
April 28, 1993
J. Arthur Loose
Tim McCreight, Department Head
Alan Perry, Instructor
Introduction
What is Niello?
Niello is most commonly an alloy of silver, copper and lead which is
'...converted with the addition of sulphur into a mixture of sulphides.'
(Fike, p.1) As the formula for niello requires an alloy fused with sulphur,
it is referred to as a metallic sulphide compound. (Untract, p.382) Niello
is called a fusion inlaid alloy, which means that is is flooded over an
uneven surface with a higher melting point. The excess niello is then
lowered to the level of relief and thus exposed in contrast with the base
metal. Niello is a '...dark grey black tone with a faintly perceptible shift
to a blue cast.' (p.1) The depth of the color depends upon the depth of the
niello itself as well as the exact composition. Niello is traditionally
applied to gold and silver and the contrast created by this dark material is
striking and beautiful. The patterns '...created by the niello inlay and the
bright color of the parent metal [offer] endless possibilities of pleasing
contrast.' (Untract, p.382) Nearly every culture to have developed basic
metallurgical skill has been found to employ niello. Niello dates back as
far as '...3000 years ago in Dynastic Egypt, [where] methods were developed
for inlaying this easily fusible sulphurized alloy...' (ib.) Among others,
the '...Persians, Migration Period peoples, Greeks, Romans, Celts,
Anglo-Saxons, Germanic tribes and Byzantines,' (ib.) used niello extensively.
During the Renaissance, especially in Italy, artists such as Benvenuto
Cellini '...brought the process to a peak of perfection.' (ib.) The fact
that '...almost all European languages use the Italian term niello, from the
Latin nigellus,' (ib.) serves to remind us of their excellence in the medium.
Phillip Fike, an American metalsmith well versed in the art of niello, has
suggested that even the great tradition of the Printmaker derives from that
of the Niellist. Fike states that,
From the 15th century onward Niello has a connection, if not one
of primal importance, to the invention of Chalcography. It remains
unproven, but the evidence awaits further research. A survey of
printmaking in 15th and 16th century Italy will assert deeper speculation.
The individuals associated with [printmaking's] use, especially in the
Florentine environment, are called 'Niellists,' and their engravings, and
printed impressions lifted from them, are called 'Nielli.' (Fike, p.1)
Although niello is generally applied to silver and gold, it will also fuse to
metals '...whose melting point is considerably higher than that of the niello
alloy, such as copper, brass, bronze, nickel alloys, or steel...' (Untract,
p. 383) Niello was often used on armor and weapons from at least the ninth
century up until the 18th century. I think that perhaps there could even be
a connection in the engraving traditionally associated with contemporary
firearms, which would be well suited to niello application. In modern times,
niello production still occurs in a few centers such as Bangkok, Thailand,
where it is '...flawlessly executed,' (ib.) Southern Morocco and Russia.
Russia, in particular has a long tradition of niello use. Theophilus in his
treatise, On Divers Arts, states that '...if you study [this book]
diligently, you will find here whatever kinds of the different pigments
Byzantium possesses and their mixtures; whatever Russia has learned in the
working of enamels and the variegation of niello...' (Theophilus, p.13) Even
today this tradition lives on in the Vologda Region, '...where a contemporary
factory called Northern Niello continues the production of niello ornamented
jewelry...' (Untract, p.382) In the Western world, niello is employed almost
entirely within the 'studio art,' context...metalsmiths such as Phillip Fike
who both create the material and use it. I know of only two commercial
sources for niello, one in Germany (Karl Fischer of Pforzheim, W. Germany)
and a California-based company whose flier I have from 10 or 15 years ago.
The commercial production centers who do not sell niello refuse to disclose
their secrets and I believe this is the proper course. Companies who market
raw niello seek to undermine the true nature of niello. As Phillip Fike
says, '...The artist, artisan or craftsman, i.e. a niellist, in control of
the materials and techniques associated with niellowork, I believe, will
begin to agree that this art was born deep in Alchemy...' (Fike, p.1) I
stand firm by this belief, understanding that Alchemy is an endeavor of the
spirit, and thus niello as well.
Oh, thou discreetest of readers, marvel not that I have given
so much time in writing about all this, but know that I have not
even said half of what is needed in this same art, the which in
truth would engage a man's whole energies,
and make him practise no other art at all.
-Benvenuto Cellini on the Art of Niello, from The Treatises on Goldsmithing
and Sculpture.
All of the original trials resulted in pieces that looked much like this one;
without the bracteate-like attachment. They are periodically referenced in the
descriptions. Some of them are still in the original thesis at MeCA. I will
attempt to photograph what is left of them the next time I visit...
Recipes with Specific Procedures
Cellini, Heinrich, Fike, Theophilus
Cellini:
1 part Silver,2 parts Copper,3 parts Lead, Sulphur in excess
The Making
The Treatises of Benvenuto Cellini on Goldsmithing and Sculpture, published
first in 1568, just three years before Celliniıs death, offer a first-hand
account of the Rennaisance art of Niello. Cellini devotes his first chapter
to this art which '...in [his] youth from [his] 15th to [his] 18th year [he]
wrought a good deal at...always from [his] own designs, and was much praised
for [his] work.' (p.9) Celliniıs recipe calls for '...an ounce of the finest
silver, two ounces of copper well purified, and three ounces of lead as pure
as you can possibly get it.' (p.7) Cellini then melts the silver & the
copper in '...a crucible in a goldsmithıs blast-furnace...' (ib.) When the
two are fully melted the lead is added and he advises that charcoal be used
to remove the scum which '...the lead, according to its wont, will make.'
(ib.) Cellini then fills '...a little earthenware flask about as big as your
fist,' and a neck not '...wider than might hold one of your fingers,' (ib.)
with sulphur, finely ground. Into this flask Cellini pours the molten metal,
'...while quite fluid and hot.' (ib.) Cellini agitates the flask, stopped up
with clay, until it is cold. The flask is then broken and the '...little
grains,' (ib.) removed. This process is repeated twice (with the addition of
a 'grain,' (ib.) of borax at the melting stage.)
I began by finding a potter who could create Celliniıs 'little earthenware
flasks,' and here I must give credit to Kate Prideau. As Cellini describes
them, they were '...about as big as [her] fist with necks not ...wider than
might hold one of [her] fingers.' (ib.) These flasks I had made worked quite
well. I melted the silver and copper in the crucible with the oxy-propane
torch, contrary to Celliniıs 'goldsmithıs blast-furnace' though I feel that
is likely of little consequence. To this molten metal I added the lead which
owing to its volume almost didnıt melt. When molten I removed the ³little
scum,² and poured into the flask which soon began emitting a sulphur plume.
I stopped up the flask with 'a little clay,' and began to 'agitate' it,
holding it in an insulated glove. Take heed! Cellini has forgotten to
enlighten the foolish who make sulphur-niello bombs by creating pressure
chambers full of the burning stuff. I will spare you this excitement and
tell you not to stop it up too tightly. Upon breaking the flask I found a
little niello meteorite all black and crusty. The sulphur had not entirely
burned off so I allowed for this before adding the re-molten mixture to the
second flask full of sulphur. The first flask had also a crust formed around
the inside, where the sulphur and traces of niello had attached themselves
most fervently. I had to break the flask nearly to powder in order to
reclaim the niello granules. In the process I inadvertently incorporated
some of the ceramic into the remelted niello. ( In an attempt to avoid this
situation I first tried to flux the inside of a flask with borax, but the
heat required to melt the borax cracked the flask. Perhaps pouring the borax
in the flask while it is still in the kiln would work.) At any rate I shook
the second flask until it sounded like there was solidified niello inside and
then I poured out the liquid sulphur before it solidified. This allieviated
the crusty-niello problem, which occured as a result of letting it all cool
together for too long. I broke the second flask and repeated all of this
again until I discovered another oversight. The nugget of niello created by
this process still had sulphur all over it. This makes it impractical to use
straight from the flask. I remelted a fourth time (and inadvertently spilled
about half the niello,) and waited for the sulphur to burn off...it seemed
infused into the niello so that if I stirred it flames erupted out once
again, and this continued for quite some time. Eventually I poured it out
into the angle-iron while a minute purple flame traced its path. The result
was one of the best looking rods to date...extremely shiny, deep black and
crisp when broken.
In order to compare methods and formulas I then made a batch of Celliniıs
niello according to Fike, with the exception that I poured it on a steel
plate as von Nuemannıs book suggests. The niello formed a hard, black cookie
that had shapes on the top suggestive of underlying bubbles. Cutting through
the diameter of one of these structures revealed that it was merely niello
which had, for some reason, formed these raised areas. Upon breaking, the
cookie showed an even, crystalline-like fracture...shiny mica-like
formations.
The Application
(Using the niello made according to Cellini)
I took a piece of the niello and ground it finely upon a steel plate with a
hammer, using a slow, crushing motion rather than striking. Cellini suggests
pliers but I found it difficult to contain the flying pieces. Careful to
grind it to '...grains & not to a powder,' (p.8) I then washed the niello
according to Cellini & placed it upon the silver sample to the '...thickness
of the back of a table-knife.' (ib.) I powdered over it '...a little ground
borax,² but ³...not too much.' (ib.) Rather than the heat of the forge, I
used an acetylene torch and heated from beneath while holding the piece in my
tweezer-like tongs. Soon the niello flowed quite evenly and upon removal of
the excess stuff I found a relatively good sample with only minor
pitting...perhaps due to holes already existant in the sample.
(Using the niello made according to Fike)
I took a small section of the rod and crushed it to grains on an anvil, using
a hammer and a slow, grinding motion. I took the grains, washed them in
water and placed them on the sample to the depth '...of the back of a table
knife.' (p.8) I sprinkled a bit of borax on it and heated it from below with
an acetylene torch. The flux bubbled, glazed and then the niello melted;
forming a pool of liquid black stuff. The sample when cleaned was dark and
clear. There are some small bubbles visible in the niello, but perhaps if I
had burnished it as Cellini calls for I would have '...stopped [them] up.'
(p.9)
The Assessment
Celliniıs method of making seems to me a little excessive for todayıs
metalsmith. The ³flask² system is wasteful and a bit more dangerous than
other methods. The final product is not any better than by other methods; in
fact, it is more likely to have foreign matter in the form of ceramic
particles. The sample does not display any qualities over the second that
leads me to believe Celliniıs method works better than any other. The second
result, (made like Fike) was a good niello flow with only some minor pitting.
The details of the stamping are slightly unclear, but I canıt find just one
conclusive reason. Perhaps the stamping itself is to blame or perhaps, as
the slight pitting might suggest, the niello with its high lead content ate
through the finer details. In contrast to his method of making, Celliniıs
method of applying works quite well for the modern metalsmith. Replacing the
forge with a torch poses only one question...would the charcoal-fed forge
create an advantageous reducing atmosphere? Whether the answer be yes or no,
I think it is probably incidental to Celliniıs thinking...more likely it was
simply the best available heat source in his day.
Fike:
6 parts Silver,2 parts Copper,2 parts Lead, Sulphur in excess
The Making
Phillip Fike, as a modern niellist, describes the making of niello in a much
more relevant manner than most sources. Fike recommends using an ordinary
Burno crucible into which copper and subsequently silver are melted with an
oxy-acetylene torch. When the two metals are fully blended, Fike adds the
lead and swirls the crucible to mix the '...alloying mass gently.' (p.5) At
this point Fike suggests that the proper swirling motion requires an
accompanying sway of the backside. Once the alloy has been properly swirled,
Fike introduces a '...heaping tablespoon of sulphur onto the alloy,' (ib.)
This should be done '...without hesitation or timidity, as the sulphur is
immediately afire, and so may be the spoon, which you might return to the
bottle, possibly afire without knowing it...' (ib.) Fike then uses an iron
stirring rod to '...'muddle' everything that is melting and burning,' (p.6)
After burning off all of the sulphur '...the niello will be at about 1200° F
a medium red color if you can read it.' (ib.) The alloy is now rotated as
before in order that '...it [washes] over itself in a circular flow. A
cinder of residue will form as the mixture cools.' (ib.) Fike maintains that
this cinder is a '...critical point,' (ib.) as it '...might in fact have a
cleansing effect on the balance of the melt.' (p.5,) When this cinder has
formed from about 1/3 of the original mixture, the niello is poured in the
angle iron (coated with carbon.)
The Application
Fike first states that the metal to receive the niello be carefully cleaned
by abrasive scrubbing, pickling & degreasing, sandblasting or
electro-cleaning. The work is fluxed with white pasting flux diluted 25%;
Batterns flux (full strength) or as I recall from a workshop I attended, a
50/50 mix of handy flux & Prip's. If using the rod straight from the pour,
the work is '...lightly fluxed,' (p.7) using one of the aforementioned
mixtures. When the flux is '...fully active and glazing the surfaces,' (ib.)
the rod is put to the hot metal. If using a powdered niello, it is
'...mixed with the flux, and then fired such as with enamel in a kiln...'
(ib.) According to Fike, '...niello is a quick moving liquid at 1000
degrees. It becomes firm [at] about 875°' (ib.)
The Assessment
I followed Fikeıs directions quite closely as they are written for the modern
metalsmith. This is, in fact, the method with which I am most familiar and
the only method I have actually been shown . I ran into no problems save the
exact timing of the pour...but I have become better at this. My first batch
was repoured once, and the second pour of the first batch came out with a
very clean, shiny surface and broke clean and crisp, with uniform black ends.
Upon application in the rod form, the niello flowed quickly and smoothly.
The cleaned sample shows sharp edges and no pitting, although there are some
minor holes that could probably be filled. On the whole I find Fikeıs methods
refined, they seem to work well and Fike himself maintains that '...research
of other published formulae with proportions vastly uneven for every
ingredient, turned [his] attention to methods as the main key to
manufacturing a fine niello.' (p.6)
Heinrich:
1 part Silver,2 parts Copper,3 parts Lead,6 parts Sulphur
The Making
Mr. Leonard Heinrich has the job of my envy: Armorer for the Metropolitan
Museum of Art. He has apparently repaired many objects with these methods of
making & applying niello. The silver, copper & lead are melted and stirred as
in Fike. This mixture is poured into another crucible which contains the
sulphur. Some recipes call for the sulphur to be molten before the alloy is
introduced. I chose to simply drop it in the powder & observe the results.
The sulphur immediately became aflame with the heat of the metal and soon the
crucible was filled with a black tar-like substance. Heinrich now says to
cover the crucible and allow it to cool. When I came back to the mixture, the
molten sulphur was hardened in the bottom of the crucible. After much
head-scratching I decided to reheat the sulphur to a liquid state and search
for the niello with tweezers. I soon discovered a black nugget which I
melted down as called for in the recipe. Heinrich pours his niello through a
sifting screen and into a bowl of water and I followed his example...Take
heed!!! The niello makes a frightful noise upon cooling. After washing the
mixture by running cold water over the bowl I set it out to dry in the sun.
This method of pouring into water creates niello particles as fine as powder
and as large as pellets. I ground up an even cross-section of this material
on a steel slab (Heinrich calls for an agate mortar and pestle).
The Application
Heinrich, like Fike, wets his work with handy flux the consistency of milk.
However, here Heinrich departs and makes a paste out of the niello and a
saturated ammonium-chloride solution which he applies as an enamel. I
continued to follow Heinrichıs directions and heated the sample from below on
a steel plate. The venting hood pulled the plume of grey smoke which
subsequently flew from the sample as a result of the ammonium-chloride
solution. The niello eventually melted and flowed evenly; however, when the
sample cooled it had an uneven surface with a grey crust in places.
The Assessment
The first thing I noticed as I scraped off the niello was that it was much
harder than other nielloes. A triangluar scraper barely cut into the stuff
and when it did it bit too deeply; chiseling rather than scraping. I sanded
the sample down with a 180 grit and even then it took some time. As I moved
down the layers I began to notice many small bubbles. These stopped just
short of the surface for the most part but there are a few pits and holes
visible in the final product. Some of the areas show larger outlines than the
stamp made; I thought that perhaps I simply wasnıt down to the level of the
relief but then as I sanded further other areas began to disappear. This and
the area on the back of the sample (behind the first 'I') lead me to believe
that the lead had began to eat the silver. The greyish cast still visible in
the recesses of the sample and prominent on the unfinished surface of the
melt are further indicators of this hungry lead. (Persian #1 & Thai for
example.) As I heated the plate from beneath I watched closely for the signs
of melting...but before the niello actually melted it turned a dry grey. I
think the ammonium-chloride had something to do with it as the niello turned
grey precisely after the smoke from the ammonium-chloride ceased. It was
also the same color as the smoke itself...an intuitive judgment on my part.
Perhaps the plate used to heat the sample on was too thick (1/8 inch)...I think
possibly that the sample may have heated too slowly...would a thinner plate
heat quicker and thus better? The fault most likely rests with the method
itself or my personal experience with the method rather than the formula. As
the Armorer for the Metropolitan, perhaps Heinrich is used to working on
larger pieces with steel and silver damascening all creating a different set
of circumstances and factors.
Theophilus:
4 parts Silver,2 parts Copper,1 part Lead, Sulphur in excess
The Making
Theophilus gives a very good account of the Dark Ages method of making and
applying niello. Theophilus divides the metal, placing the copper and the
silver together in a casting crucible. He then states, 'Take yellow sulphur
and crush it small; put the lead and some of the sulphur into another casting
crucible.' (p.104) The silver & copper are melted, mixed and the crucible
containing the lead and a portion of sulphur is added. This is '...mixed
again vigorously with a piece of charcoal,' and poured '...into the other
casting crucible over the sulphur,' which has been '...put therein.' (ib.)
This crucible is then '...put into the fire until [its contents] melt.' (ib.)
It is stirred once again and poured into an iron ingot mold. Before it
hardens it is hammered, heated slightly and hammered again, '...For the
nature of niello is such that, if it is hammered when cold, it immediately
breaks up and flies into pieces; on the other hand it should not be heated so
much as to become red because it immediately melts and runs into the ashes.'
(ib.) When the niello is thin, it is placed in a deep pot of water and
crushed with a pestle until it is extremely fine. It is then placed in a
goose-quill which is stopped up. Fike has suggested that the goose-quills
serve as airtight containers for the powder, which is more liable to break
down in the presence of oxygen.
I followed these directions as closely as possible, given the thousand years
or so between author and artist. I melted the silver & copper, stirred with
charcoal and added the lead/sulphur mixture. This I then poured over the
other crucible with the sulphur in it. I heated this crucible from the
bottom and sides first, mimicking the effect of a forge fire to the best of
my ability. The sulphur soon melted and I played my oxy-propane torch over
the niello itself and waited until the sulphur had burned off entirely. I
poured into the angle-iron, waited for it to cool slightly, placed it with
tweezers on the anvil and pounded lightly. I placed it in water and ground
away...an excellent solution to the problem of ³springing niello aside.² I
set it in the sun to dry.
The Application
Theophilus takes '...some of the resin called borax,' (p.105) and grinds
'...a small piece of it with water in the same pot, [not the pot of water the
niello was ground in] so that the water is rendered just turbid from it.'
(ib.) The place you want to cover with niello is wet with this water and the
quill is tapped to drop powder over the area until '...you have covered it
all.' (ib.) Theophilus then places the object to be nielloed in a heap of
'...well burning coals,' taking care that '...no coal is placed over the
niello or can fall on it.' (ib.) Theophilus goes on to state that '...If
[the niello] does not become full everywhere at the first heating, wet it
again and put niello on as before, and take good care that more is not
needed.' (ib.)
I also followed Theophilusı directions for application rather closely.
Modern borax already comes with water in a hydrous form. Therefore, to
simply apply this powder has a similar effect to mixing the prepared
solution. I did not use goose-quills but presumed that a ziplock baggie may
perform the twentieth century funtion. Niether did I use coals, and this may
prove to have something to do with my results; coals have a reducing effect
and several niellists suggest that a reducing atmosphere is benificial to a
good niello flow; mine has silver in it as well as pitting.
The Assessment
Theophilusı method seems adequate for his day. The word
'torch' may be substituted for 'forge,' and the text reads contemporary up
until the goose-quills. I think perhaps the sulphur that is added along with
the lead during the first melt is extraneous, but I donıt think it would
cause any harm either. The method of grinding underwater neatly solves a
messy problem and Theophilus has acknowledged the deterioration of niello in
the presence of oxygen; something others have not. Applying the niello in
powder form with borax seems to work well enough, unless perhaps it is a
contributing factor to the recrystallization that occured in my sample.
Borax melts a bit higher than other fluxes and may thus have caused me to
overheat the sample. Theophilusı warning about re-heating niello is also
sound advice, as some of my earliest attempts to repair niello have shown.
On the whole I think that this niello formula should work as well as any
other. Theophilusı methods could only be improved slightly with todayıs
technologies. Theophilus probably knows his niello and I think that the
recrystallization is likely the result of the borax flux...another paper
might tell us whether or not there were other fluxes available for Theophilus
to have used instead. It might also tell us whether the borax of Theophilus
is the borax of today or even if a translatorıs error is at hand.
Recipes without Specific Procedures
Augsberg #1 Bolas #1 Karmasch Modern French Persian #1 & #2 Pewter Experiment
Pliny Rucklin #1 & #2 Russian Spon Thai Wilson
Augsberg #1:
1 part Silver,1 part Copper,2 parts Lead,Sulphur in excess (1/2
cup)
The Making
I first made Augsberg #1 in the manner of Fike, pouring the melt into an
angle iron at about a 20° incline. The first cast had a silver line running
down the underside. This is indicative of a bad pour wherein the silver has
recrystallized as the result of it taking place at too high a temperature.
(Fike) It also had an iridescent surface toward the end of the pour and a
collapsed length of about six or seven inches at the front. I broke up the
niello which was slightly malleable and made a distinctly crunchy noise. The
broken ends appeared solid silver, solid grey and mixed. (These all indicate
an uneven pour.) After remelting and adding sulphur once again (Fike) I
poured into the same iron with what appeared to be a better result. The
niello had an even, dark tone and the ends seemed relatively even when
broken. The surface was a dull matte; according to Fike it should ideally
exhibit a clear, shiny surface.
The Application
Upon application Augsberg #1 flowed easily across the surface of the silver
sample. Again I applied the ³Splendid Rod² in the manner of Fike, using an
acetylene torch with a reducing flame and a flux of 50/50 Prip's & handy.
The flame was played primarily underneath the sample with a steel screen
supporting. Upon removal, the sample revealed both small areas of pitting
and small areas unfilled. These were slight enough that I believe they were
the fault of the application process and not the niello itself. I then
attempted to apply Augsberg #1 to a cylindrical bead about one-half inch
thick by about an inch in diameter. The bead had an overlay design, using
the niello as a negative element. To apply the niello I set a hand drill in
a bench vise and had an assistant turn it at a slow rate. A small rod of
tapered steel affixed the bead to the rotating drill. Again I used the 50/50
mix suggested by Fike and the acetylene torch. Once I had sufficiently
covered the bead (to all appearances) I began filing down the surface of the
niello only to uncover small unfilled areas. My best guess is that these are
the result of both an uneven application and the sheer depth of the area
filled (about 1/8².) Several times did I attempt to fill these small spaces
only to discover that I had recrystallized small areas of silver in the
niello.
The Assessment
I suspect that most of the problems encountered with regard to Augsberg #1
are the result of my own inexperience with the material. In the course of
this study I have become more sensitive to the point at which molten niello
should be poured. I suspect that even the second pour was made a bit too
soon, while the metal was too hot. Pouring too hot seems to result in the
aforementioned silver vein running through the length of a rod-like casting.
It also results in the collapsed section of the rod where, like a lava
tunnel, the outer skin of the pour cools and hardens before the inside, which
continues to run down the length of the angle iron. Both of these sections
are bad niello, for they contain differing amounts of the components of the
alloy. As far as the application process goes, I also believe that my methods
are more at fault than any quality intrinsic to the composition of this
particular formula. Re-heating niello is ill-advised by almost any source
and Fike specifically cites this as a probable cause of silver
recrystallization.
Bolas #1:
2 parts Silver,4 parts Copper,1 part Lead, Sulphur in excess
The Making
Bolas #1 is an alloy low in lead and high in copper. I melted the copper
first because of its sheer volume, added the silver, a pinch of borax and
swirled the alloy. To this I added the lead which disappeared in an instant.
I muddled in several heaping tablespoons of sulphur with a steel rod and
burned it off completely. I swirled the mixture as it cooled to form the
cinder and poured into the angle-iron. The pour contained roughly half of
the original alloy as the rest lay hardened in the crucible. The mixture had
solidified quicker than most, perhaps because of the high copper content. I
melted the remaining cinder, swirled again and poured as before. I now had
two rods, one from the original melt, one from the cinder, and the remaining
bit of drudge from the cinder of both pours. Both pours were
uncharacteristically red as they cooled in the angle-iron...again I suspect
because of the high copper content relative to the content of lead. The
redness was concentrated near the front which suggested an uneven pour...upon
breaking both rods had silver veins. I remelted both together in an attempt
to re-fuse the elements and get a good pour. I re-sulphinated the alloy
(Fike) and poured it off again with results very much similar to the previous
pours.
The Application
I took what appeared to be a good section of the rod, an area from about the
middle, just after the area which glowed red for longer than the rest. This
area of excess heat lay toward the front of the pour in a globular shape
thicker than the remainder. I fluxed the sample with a dilute mixture of
handy flux and heated from below with an acetylene flame over a steel screen.
The sample achieved a high temperature and still the niello would not melt
so I heated the niello itself. I was able to drop melted sections of the
niello onto the heated sample but it would not flow. The result is a
globular mass atop the silver sample. The niello as it exists would be
completely incapable of fusing any area of intricate design.
The Assessment
It seems that the high content of copper relative to the lead
created a niello reluctant to melt and flow. The redness observed during
every pour would indicate this reluctance to flowing...most nielloes
exhibiting a red glow are still fluid. The alloyıs inhibited flow also
determined the poor result of the sample...a small spot on the back suggests
some silver dissolving into the lead. I think that perhaps this high copper
to lead ratio makes for a niello whose properties might work better on a
material with a higher melting point...perhaps even steel. In general it
seems fair to say that Bolas #1 is a niello ill-suited for either Fikeıs
method of pouring into an angle-iron as the direction of the flow makes it
easier for the alloy to separate into heavier elements. It also seems fair
to suggest that the alloy might be better used on other materials although
the qualities of the niello might alter when made differently.
Karmasch
15 parts Silver,90 parts Copper,150 parts Lead,750 parts Sulphur
The Making
Karmasch, an 18th century Russian niellist, recorded this mixture and it has
come to my attention through Robert von Nuemannıs book. I melted the silver
and the copper in a crucible, swirled it, added the lead and stirred. In
response to Heinrichıs recipe where I poured the niello into powdered sulphur
I melted the sulphur prior to introducing the alloy just for comparison. This
is the method described in von Nuemannıs book. The niello disappeared into
the black, flaming puddle. I added sulphur and allowed the stuff to cool. At
this point the method described becomes vague. Do I remove the niello from
the mixture (to be remelted according to von Nuemann,) or do I burn the
sulphur off entirely? For the sake of comparison I burned off the remainder
of the sulphur, which took a while but produced a perfectly acceptable
result...I poured the niello into the angle iron & it came out with all the
signs of a good pour...deep, rich, blue-black, a shiny surface all around and
exhibiting no evidence of silver recrystallization.
The Application
I applied Karmasch to the sample in the rod form using a thin mixture of
handy flux. The niello flowed smoothly and flooded the surface of the
silver. The only problem I encountered during the application process was
the flux which bubbled up and had to be removed with a solder pick. I removed
the niello with a triangular scraper and sanded down with a 220 grit
sandpaper. There were only a few depressions in the niello that showed as
pits...a reflooding would probably eliminate them. I burnished the sample in
an attemt to see if that would work to smooth them down. Burnishing gave the
sample a shiny surface which makes the niello difficult to see in certain
light. This effect is not necessarily undesireable although it also has the
effect of blurring the lines of the niello.
The Assessment
I found Karmasch to be an excellent formula although I am uncertain whether
or not the formula itself deserves the honors. Perhaps the method of pouring
the alloy into molten sulphur is a more effective method or perhaps Iım
merely becoming more profficient. My general experience is contradicted by
the success of this niello; most formulae high in lead have been the source
of much frustration.
Modern French:
30 parts Silver,72 parts Copper,50 parts Lead,384 parts
Sulphur,36 parts Borax
The Making
I made Modern French in the method of Fike, melting the silver & copper
together in a crucible with the oxy-propane torch. I then mistakenly ommited
the lead and proceded to the next step. I added the borax & sulphur already
mixed together to watch what would happen. The mixture flamed as usual and
eventually the sulphur burned off...nothing out of the ordinary until I
poured the alloy onto the steel plate where it cooled with a red glow in a
thick flow. I then discovered the lead I had forgotten sitting atop the
venting hood. I remelted the alloy and added the lead. I poured the niello
onto the steel plate where it cooled with a small red glowing spot off to one
side. I then attempted to hammer the cookie as it '...hardens and embrittles
the alloy which makes it easier to break up.' (Untract. p. 385) Upon
breaking the newfound cookie I discovered a small silver bead with a
crystalline surface that the niello itself did not adhere to. In order to
see what, if any effect this might have upon the niello I went ahead and
applied it without any portion of the silver bead.
The Application
I pasted the silver sample with handy flux diluted to about 25% and placed
the granules of niello evenly across the surface. The granules were about 3
mm square and were placed about 1 mm from each other. I then coated the
niello with more handy flux (diluted) and heated from below on a steel
screen. The flux bubbled, the niello went grey for a few seconds and then
turned completely liquid and black. It flowed evenly and true with the only
obstruction being a large blob of flux. I deftly removed the offending blob
with a pluck of the tweezers and let the sample cool.
The Assessment
The niello cleaned off easily and produced and even greyish tone. It is not
as dark as some, but it fused and flowed just as well as any other. Some
areas, particularly the lower right leg of my little 'Eiffel tower,' show
excellent detail. I cannot say how much of this has been affected by either
the late addition of lead or the methods of making & application. It would
seem fair to say that none of these factors proved detrimental.
Persian #1:
1 part Silver,5 parts Copper,7 Lead,24.5 parts Sulphur
The Making
I made Persian #1 according to Fike, using the oxy-propane torch and the
burno crucible. The silver & copper melted less easily than other formulas,
perhaps because of the higher percentage of copper. The addition of the lead
made a greenish light for an instant and made a silvey grey liquid with a
mercuric look about it. The lead I added by the spoonful, 'muddling' it in
as in Fikeıs method. This took quite some time and the sulphur seemed to
form a crust that was often hard to penetrate with my iron stirring rod.
While I fussed about with this sulphuric crust the alloy below it cooled off
and when I finally poked through, it had solidified. This tedious process I
repeated several times until all 24.5 grams of sulphur were gone. When I
poured the niello it came out with a dull matted surface. Upon breaking it
was obvious that I had an uneven cast: the end of the pour was a smooth,
friable U-shaped rod while the front was a rough, round, pliable bit of
stuff.
The Application
I chose a piece from the middle and applied it in rod form to
a sample with a 50/50 mix of Prip's and handy flux. The niello turned a
bright red and seemed not to want to melt, then began to eat silver. I
remelted the remainder of the niello and recast it. I applied in the same
manner and I got very similar results, right down to the second sample, also
discussed below. I saved some of the second rod and remelted the other
sections with any appearance of hope; the front of the pour after the 'U'
shape started to become rounded but before it got truly rough and ugly. This
remelt cast with a slightly better appearance and a slightly better result.
The Assessment
This Persian niello failed to show any redeeming qualities
whatsoever. Each remelt failed to pour well and each sample failed to fuse
with the possible exception of the third. The first sample began to fuse
only after I took the silver to a glowing orange where it actually started
curling at the edges. The second sample also failed to fuse even at an
extremely high temperature...in fact, the second sample merely began eating
the parent silver away. The third sample fused only at a high temperature
with evidence of pitting and muddled tones. The only unusual factors I can
come up with are the high percentages of copper and lead relative to most
other recipes. The matter of the sulphuration may also have some unknown
effect on the quality of the niello. I am more moved to blame the formula
itself as I received similar results with a similar niello, namely the Thai
mixture. The evidence seems to support a theory that these mixtures simply
donıt work very well.
Persian #2
15.3 parts Silver,76 parts Copper,106 parts Lead,367 parts Sulphur,76 parts Ammonium-Chloride
The Making
I made the second Persian niello by melting the silver & copper together,
swirling, adding the lead and stirring. I poured in the ammonium-chloride
and observed as it burned off with a grey stream of smoke. When the grey
plume had ceased to fly I added the sulphur which burned off with its
characteristic yellow smoke and blue flame; indeed, this was the most
aesthetically pleasing of all the nielloes to date. I allowed the alloy to
cool, wash over itself and when I finally released it down the angle iron it
flowed both longer and more liquid than usual. It cooled and soon the niello
broke up into segments about 2 to 4 inches in length which began to bend
upwards at the ends. The niello had a deep black surface with a distinct
shine...some of the ends had drops with exceptionally shiny dark surfaces.
The Application
I applied Persian #2 in rod form with a dilute mix of handy flux. The niello
flowed easily enough and I thought I had a good sample. When I scraped the
surface I soon observed that some of the larger areas were depressed. I
reapplied niello to these areas and allowed the sample to cool. Upon final
cleaning the sample showed areas of recrystallization (the lower part of the
³R²) and unexplained areas of unusual size (the 'E' should be much smaller).
The tone of the niello is not now nearly as deep as I had thought it might
be, judging by the color of the original rod.
The Assessment
Persian #2, another niello high in lead, seems somewhat problematic. I can
come up with no reason for the recrystallization and the areas of unusual
size. I am also positive that the first time I applied Persian #2 to the
sample the unfilled areas were filled...perhaps it contracted as it cooled or
the large areas may be the result of an early stage of niello eating silver.
In any case I was surprised by the results of the sample when the original
pour looked so good.
Pewter experiment:
2 parts Silver,2 parts Copper,6 parts Pewter, Sulphur in
excess
The Making
In order to impose as many controls as possible (admittedly not enough to be
properly scientific) I substituted pewter for lead and used Fikeian recipe
and methods. I melted the silver & copper, added the pewter as usual and
muddled the sulphur in, all the while executing the proper swirls and
backside motions. At the moment of pour I watched as a silvery rod of liquid
shot out of the black front of the cast. I remelted several times and always
came out with the same results...the pewter was not fusing with the alloy and
would remain liquid long enough to come out of the front of the pour.
The Application
Attempts to fuse the stuff proved completely useless.
The Assessment
I suspect that the pewter either has too low of a melting point or does not
become a sulphite as do silver, copper and lead. I make this assumption
based on the observation that the metal shooting out the front of the pour is
not blackened.
Pliny
3 parts Silver,1 part Copper,2 parts Sulphur
The Making
The Pliny formula is an unusual niello as it calls for absolutely no metal to
lower the melting point. Herbert Maryon, speaking of a Roman niello states
that '...This niello was composed of silver sulphide only: a material which
became plastic far below itıs melting point. In powdered form it may be
filled into recesses in a work, and after gentle heating it may be moulded
and burnished to its final level.' (p.161-162) I had many problems with this
niello. The first being that the alloy was not mixing entirely. Upon
casting the rod it, appeared slightly less fluid than a normal niello. Upon
breaking (or sawing, as the case may be, for it is not friable at all) the
'broken' ends revealed a brassy substance which is most likely the
un-sulphured alloy of the silver and copper.
The Application
I found a section of the rod with less of this un-sulphured alloy than other
areas and filed it down powder. I placed this powder on the sample and
fluxed it with Prip's flux. I heated it up and watched as the piece heated
to dull red with no observable changes. I attempted to 'burnish' the
material in with a polished steel rod with no real success. Upon cooling the
sample bore a rough, dark coppery surface with obvious granules from the
filing. This was much more difficult to remove than the normal nielloes; a
steel scraper had little to no effect. On reaching a level surface, the
sample showed the same brassy alloy fused into areas of the base metal. Some
areas show a dark color infused into the metal. This dark color is not a
patina; it is probably the result of particles of the ensulphured alloy that
fused to the sample.
The Assessment
This formula does not seem to want to fuse into a uniform alloy. Both times
I attempted to make this alloy the outer surface of the pour appeared to be a
sulphite but the interior showed a pure silver/copper alloy. Both materials
have a very high melting point and therefore the niello is not applied in the
same flooding manner as most. There must be both a way of making the alloy
and a way of applying the alloy with which I am not familiar. Upon discovery
of these methods I am sure that the formula would work just fine, if not very
differently from other recipes.
Rucklin #1:
3 parts Silver,5 parts Copper,7 parts Lead,6 parts Sulphur,2
parts Ammonium-Chloride,24 parts Borax.
The Making
Rucklin #1 seems problematic right from the start. The 24 parts borax simply
seems odd...borax just makes a liquid and I couldnıt see why it would create
a part of the alloy. I decided to melt the ammonium-chloride and the borax
in a separate crucible into which I would pour the (en-sulphured) alloy of
silver, copper & lead. I chose to do this in spite of the previous
experiments wherein the sulphur was mixed in with the other powders either
melted or not. I could find no sources with an explanation of what to do
with such an odd recipe. I melted the silver, copper & the large amount of
lead into the crucible and meanwhile melted the borax in a large crucible...I
do not know whether Rucklin intended hydrous borax or an-hydrous borax. I
used a hydrous borax. The small amount of ammonium-chloride produced a mild
plume of grey smoke and when the solution was molten I added the molten alloy
as well. The alloy swirled about, hardened and settled on the bottom of the
crucible. I poured out the mixture into a steel plate and allowed it to
cool. The niello sat in the middle of the black, glassy, friable remnant of
the borax/ammonium-chloride mixture. The glass easily breaks and separates
from the small button of niello and where it does separate there is a silver
crystalline surface exposed on the niello.
The Application
I fluxed the sample with a dilute mixture of handy flux. I hammered the
niello blob in an attempt to break it up. Instead it just forged flat like a
normal metal ingot. I heated the sample and applied the niello in flat,
cookie form...holding the piece of niello to the surface of the sample. The
niello touched the hot metal and flashed a dark color across the surface of
the sample. Un-like the normal flow of niello, this was purely a surface
reaction on the sample. Soon the rest of the niello began to flow more like
a normal application with the exception that the niello was more of a
silvery, mercuric flow. When the sample cooled it had a rough surface with
hard projections sticking out. These projections were not at all
friable...the only way to remove them was to file them off. As I sanded down
through the layer of niello I noticed that it was not at all black as in
usual nielloes. When I finally got down to the parent metal it was obvious
that this niello was extremely flawed...the relief is filled with a dull,
brassy material not at all niello-like, perhaps mostly silver.
The Assessment
Rucklin #1 is a niello that I was unsure about from the beginning. I did not
know where the large portion of borax was to figure into the formula. The
only possibility I can come up with is that the sulphur, ammonium-chloride
and borax all get put together (melted or in powder form) and the alloy is
poured in as with other formulas. While that is more likely the solution it
is not necessarily so...even with recipes that pre-mix the non-metal elements
there is still no precedent for so much borax. I donıt know why the niello
applied so poorly although Iım not surprised that it did. The blob that
formed in the borax seemed uniform when I inspected it. The forgeable
quality of the original ingot is indicative of some anomaly. The content of
silver, copper and lead should have made it friable like any other niello.
Obviously something isnıt right with either my methods or the high content of
borax in this recipe.
Rucklin #2:
1 part Silver,2 parts Copper,4 parts Lead,5 parts Sulphur
The Making
Rucklin #2 I made by melting together the silver & copper with an oxy-propane
torch in a burno crucible. I added a pinch of borax at the point of melting
and added the lead...muddled in the sulphur with an iron rod and poured after
swirling a cinder into the crucible. I used one ounce as a part and ended up
with one of the largest rods to date, nearly 2 1/2 feet long. Most of the
pour looks good (clean breaks, shiny surfaces, rounded rod and etc...) The
only anomaly was at the front of the pour where a small bead of silver
appears to have crystallized...the rest of the pour seems void of any silver
veins whatsoever.
The Application
I fluxed the sample with a 50/50 mix of handy flux & Prip's. I heated the
sample from below with an acetylene flame and waited for the flux to clear.
I applied the niello in rod form from a nice mid-section piece. It flowed
clean & even...producing a flat surface across the top of the sample. This I
deftly scraped with a steel bevel and sanded down with a 180 grit followed by
a 220 grit. I finished the piece off with a bit of Scotch-brite.
The Assessment
There are only a few pits and holes in the sample. If I had burnished my
niello '...as firmly as the work would seem to admit of,' while the sample
was '...a little hotter than the hand could bear,' I would likely have
stopped up '...certain bubble-holes.' (Cellini, p.9) I think these holes are
the result of my own error as every other aspect of the niello making and
application went off without any appartent problems. The niello, while
slightly high in lead content, seems to work just fine according to the
described methods.
Russian:
1.5 parts Silver,2.5 parts Copper,3.5 parts Lead,12 parts Sulphur
The Making
I made the Russian niello by melting the silver & copper together in a
crucible, adding a pinch of borax at the point of melting and adding the
lead. Swirling & stirring the alloy, I fused it well. I poured the niello
into a container full of the 12 ounces of sulphur (unmelted.) The alloy lit
the sulphur afire and I shook the container as several sources suggest. I
left the mixture to do what it would and eventually the entire container was
a pool of molten sulphur cooling off but never quite becoming solid. This
mixture I subsequently reheated, burning off all of the sulphur and
eventually remelting the alloy. I poured off the niello into the angle-iron
and the results were very good to all appearances. The rod was thin and
broke quite easily, the niello forming more 'beaded' sections than usual.
The surface of the rod was deep and shiny.
The Application
I fluxed the sample with a dilute mixture of handy flux and
heated from below with an acetylene torch. The flux soon became clear and
the rod applied cleanly and evenly; filling every bit of the surface. Upon
removal of the niello a relatively clear result soon surfaced. The niello
had blurred the lines of the stamping slightly and showed a mild brownish
color.
The Assessment
The niello fused quickly and well, the method of pouring the molten alloy
into the dry sulphur seems to work just as well...perhaps a little more
time-consuming than pre-melting the sulphur, but the result seems just as
well. The only problem with the niello is the slight blurring of lines,
probably due to an overheating of the sample (although I was not aware of
such) or the quality of the stamp may have been such that it had a depressed
area surrounding the actual mark and thus appears large or blurred.
Spon:
.5 parts Silver,1.5 parts Copper,2.75 parts Lead,27 parts Sulphur,2.75
parts Ammonium-Chloride
The Making
Sponıs formula comes down to us with his Workshop Receipts which I was unable
to locate. My brief explanation comes from Herbert Maryonıs book Metalwork
and Enameling. The formula calls for two crucibles: one filled with the
sulphur and ammonium-chloride and the other where the metals are alloyed. I
melted the silver & copper in a burno crucible with an oxy-propane torch and
swirled, added the lead and stirred. I poured the molten alloy into the
container with the unmelted sulphur/ammonium-chloride mixture. The second
crucible immediately became afire with the heat of the molten metal and I
shook the container. The mixture eventually cooled without melting the
entire sulphur/ammonium-chloride powders. I plucked the niello nugget from
the powder with a pair of tweezers and remelted the metal to burn off
residual sulphur, then poured the niello into the angle-iron. This I did
with dubious results. The rod has a depressed front and a surface similar to
that of the Thai and Persian nielloes...rough and almost bubbly on top.
There are some very minor silver veins running through the niello rod.
The Application
Spon reduces the mixture to powder and applies with a small amount of
ammonium-chloride. Maryon states that this is the mixed with a '...solution
of sal-ammoniac [ammonium-chloride] for use.' (p. 165) To me this implies a
solution mixed with water. This is then heated until '...the composition
solders the metal.' (ib.) I applied in the usual manner of rod & dilute
handy flux with very poor results.
The Assessment
This is another example of a niello that is faulty for reasons I cannot
understand. The sample shows a dark blob of niello that I left unfiled.
Although it appears to have fused it demonstrates the nielloesı unwillingness
to flow. I took the sample to a dull red which is usually hot enough to
cause the lead to disintegrate the silver. The method of pouring the alloy
into the powder may have been faulty in that it is intended to be molten
before the introduction of the alloy. I found no evidence in the text to
suggest this and that is why I did not pre-melt the sulphur and
ammonium-chloride. The rod itself, when poured, did exhibit symptoms that
have come to mean bad niello: the bubbly surface, the collapsed surface and
silver veins. It is possible that this pour was the cause of the faults in
the niello...these traits seem to accompany the pour which occurs at too high
of a temperature, although I was not aware of pouring at excessive heat.
Generally I have also had poor results with any niello that includes
ammonium-chloride.
Thai
1 part Silver,5 parts Copper,3 parts Lead, Sulphur in excess
The Making
I melted silver & copper with the oxy-propane torch in the crucible as usual,
adding a touch of borax to insure complete melting. I swirled and added the
lead, stirred and muddled in sulphur. I paused, swirled a cinder and poured.
The rod cooled with nodules covering the surface. I filed these nodules to
determine if they were hollow, silver, copper or niello. Oddly enough, each
of these nodules seemed to be niello. Otherwise the rod broke clean and
true, with black ends and no pliable sections. I then applied the niello to
a sample with very poor results so I remelted the rod in an attempt to
somehow re-alloy the stuff. The re-sulphured rod came out with the same
nodules and suspecting those same to be either the cause or coinciding with
some quality of the pour I recast it several times. Each time I received the
same results and thus finally decided to apply the niello once again. The
second sample came out with the same poor quality as the first.
The Application
The first sample I applied in powder form, making a paste
with the 50/50 mix of handy and Prip's. The niello heated to a glowing red
but refused to melt. By the time the sample became a dull red, the niello
had begun to eat into the silver. The second sample proved to show the same
trait for which I have no real explanation.
The Assessment
This niello seems for some reason determined to fail. The percentage of lead
is relatively high but others higher in percentage have demonstrated better
results. For the nodules I have no explanation. They may or may not imply
or accompany some flaw in either the material or the process. As for the
quality of the application I can only say that this niello is somehow flawed.
Is there an aspect to the making that I am unaware? Some would say that the
Thai have secrets which allow them to make an export industry in niello.
There is speculation that they employ a reducing process which may or may not
affect the quality of this particular formula.
Wilson:
6,2,1,10
The Making
The Wilson is the formula is specifically cited by Fike as the inspiration
for his refined recipe. The '6,2,2,' of Fike honors the fact that he has
added but one part to this existing formula, even though '3,1,1,' would be
more proper. I therefore decided to manufacture Wilson in the manner of Fike
to see if there was an immediately discernable difference. I melted the
silver & copper with my oxy-propane torch, swirled the two metals and added a
pinch of borax just prior to the lead. Swirling the three with the
accompanying sway I paused to heap in a tablespoon of sulphur which I muddled
down into the burning alloy. Repeating this step twice more I allowed for
the cinder to form and poured down the angle-iron.
The Application
The rod shone forth true and dark; clear and straight; shiny
and crisp. I applied in rod form with an acetylene torch and dilute handy
flux. I obtained good results as can be seen on the sample.
The Assessment
Wilsonıs formula is an excellent one and works well with the modern
metalsmithıs most available methods. The flow was even and quick and went
off without a hitch.
Conclusion
In the process of making and applying these many nielloes I have encountered
certain difficulties and reached several general conclusions. Some of these
conjectures concern actual formulae and others concern methodology. Most of
these speculations have at least one contradictory result and some are quite
intuitive in nature. I have no absolute conclusions except that with
practise one may become better at the art of Niello. Concerning the formulae
themselves, I have enjoyed the least success with those recipes high in lead
content. The recipes Persian #1 and Thai in particular, both with very high
lead to silver ratios, exhibited similar behaviors. Both produced pours with
uneven surfaces which were U-shaped toward the front. Unlike Persian #1, the
Thai recipe produced unexplainable nodules but both recipes refused to melt,
fuse or flow upon application. I had originally predicted that a niello high
in lead would have a better flow and a lower melting point but in fact,
neither of these formulae had either quality. I also had poor results with
any recipe including ammonium-chloride. Rucklin #1, Persian #2 and Spon all
included various degrees of ammonium-chloride solutions. All provided poor
results. Further exploration might reveal if a change in methods would
demonstrate better applications. On the other hand, I had success with a
number of nielloes: Cellini (manufactured according to the same), Fike and
Wilson in particular. Most of these formulae have a higher silver to lead
ratio. Cellini is an exception but I also had difficulties with his recipe
when made according to easier, modern methods. I generally found that Fikeıs
method of making niello tended to be the most successful and least wasteful
method. Fike 'muddles' in his sulphur whereas Theophilus and others pour the
molten alloy into a container already full of sulphur. While the pouring
method seems to work just as well, it requires more sulphur than Fikeıs
method. There is also either excess sulphur to burn off or waste in the
rather unpleasant form of molten sulphur. I had better results with those
recipes that call for pre-melting the sulphur than those that did not.
Celliniıs method is by far the most wasteful and dangerous of the several
methods attempted during this thesis. Not only does Cellini waste sulphur by
filling the flasks 'half-full,' but the flasks themselves are wasted in the
process. The danger involved in handling (and agitating!) hot flasks with
molten compounds of metal and sulphur seems excessive; although it is
exciting. Considering Theophilusı methods I cannot say that Cellini was
limited to the technology of the day. I must therefore state that even
Cellini could have devised a better method. During the course of this thesis
I had also hoped to simply gain more skill in the practise of niello. I have
learned to observe several events that I believe affect the success of a
niello venture. Were I to do this thesis again entirely from the start I
have no doubt that I would immediately notice a marked increase in the
quality of all the experiments. I do not believe that this has adversely
affected the general results of this project, merely that all the nielloes
would benefit from a greater experience in the medium.
When making niello, there are many important things to observe, avoid and
encourage. It is important to stir the initial alloy that consists of only
silver and copper as I have noticed that the surface of the alloy may appear
completely molten and fluid while the bottom is not. Upon adding the sulphur
one must be certain that there is not formed a crust atop the alloy. This
crust can be extremely difficult to break and it usually causes the alloy
underneath to cool and solidify, melting the crust repeatedly keeps the
niello unnecessarily hot for too long. The crust seems more likely to form
when dealing with a larger volume of niello, possibly because it requires
more heat than a smaller volume. The last and most important event to observe
carefully is the actual pour. Phillip Fike has described the moment of the
pour as '...indescribeable,' (Fike, p.5) and I agree. My initial pours were
all made at too high a temperature, which is the cause of silver veins
running through the center of a pour. In the case of a cookie pour the
silver forms a small button in the center of the remaining alloy. The niello
must be heated appropriately to both keep it fluid and burn off excess
sulphur. It must not solidify before the pour. However, as the niello must
not be heated too high, care is needed. The pour itself takes place just as
the niello begins to solidify and this is the cause of Fike's 'cinder'. Just
as he intuitively believes that this 'cinder' is beneficial so have I also
come to believe. The signs of a good pour are obvious soon after it
solidifies. A good pour exhibits a smooth, shiny, black surface and starts
to bend upward at the ends as it cools. When broken the rod should snap
cleanly, with no malleability. Upon closer inspection the broken ends should
show a minute, crystalline surface that is evenly black. The rod should not
have a portion larger than 10 or 20% collapsed at the front of the pour and
as it cools it should glow uniformly. Any abnormalities are likely
indicative of a bad pour. (Such an anomaly was the nodules on the Thai
niello.) When applying niello I have noticed little difference in the effect
of fluxes. Prip's and Handy flux both seem to work well. An excess of flux
creates flux glass which will form holes and curved pits if not removed, and
diluting the fluxes helps alleviate this problem. A sure sign of a bad
niello is that it does not immediately melt and flow across the surface of
the base metal. It should flow quickly and evenly. It should not be heated
beyond this point or silver is likely to recrystallize. Sometimes it is
necessary to heat not only the base metal, but the niello as well and I have
had no adverse effects as a result of this as long as I did not heat the
niello too much. It is difficult to qualify much of the experience gained
herein. I know what '...heating too much,' means but I cannot convey exactly
what that is. Niello is finicky and troublesome. I believe that is very much
a reason it has fallen out of common use. Even after all of the experience
gained through this thesis I am not completely confident I will always enjoy
success when employing this technique. There is still much to be learned and
this thesis has only grazed the very surface. There are in fact several
recipes I did not have the opportunity to experiment with. Bolas #1 is made
of 2 parts antimony sulphide, one part lead sulphide and 8 parts sulphur.
Bolas #2 calls for antimony and Augsberg #2 is a mercury amalgam! I could
not obtain antimony or lead sulphide for the first two recipes and owing to
the danger presented by the Augsberg recipe I opted to leave them out.
One can easily see that of niello
'...this art, the which in truth would engage a man's whole energies, and
make him practise no other art at all,' leaves much to be explored.
Bibliography
Cellini, Benvenuto. Treatises on the Arts of Goldsmithing and Sculpture.
(Translated by C.R. Ashbee.) London: Edward Arnold, 1898; New York:
Dover Publications Inc., 1967.
Fike, Phillip. Niello Workshop Handout., Workshop at the Maine College of
Art, November, 1990.
Maryon, Herbert, O.B.E., F.S.A. Metalwork and Enamelling. 5th ed. New York:
Dover Publications Inc., 1971.
Theophilus. On Divers Arts. (Translated by John Hawthorne and Cyril Smith.)
New York: Dover Publications Inc., 1979.
Untracht, Oppi. Jewelry Concepts and Technology. New York: Doubleday, 1985.
von Nuemann, Robert. The Design and Creation of Jewelry. Revised. Radnor,
PA., Chilton Book Company, 1972.