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About the cup:
Benton, Janetta Rebold. Materials,
Methods, and Masterpieces of Medieval Art.
Praeger, 2009.
Page 166 "The earliest known
example of plique-a-jour, and one of the finest examples of this
technique, is the Merode Cup, made in the early fifteenth century in
France. This covered cup is made of silver-gilt, decorated on both
cup and cover with a band inset with panels of translucent
plique-a-jour enamel made with gold cells. This unique cup, measuring
only 6 7/8 high and 3 5/8 inches in diameter.." size of the
actual piece.
Silver gilt and plique-a-jour enamel.
The inside where the plique-a-jour panels are is plain and separated
by bands left in the metal. The plique-a-jour is held in place on the
outside with molded frames decorated with applied leaves. The outside
of the cup is decorated with pounded scrolling designs. The base of
the body is encircled by a girdle. The upper part of the foot is
decorated with pounded rosettes and encircled by a girdle. Below the
band is stamped with sunken circles pierced with holes (for the
possible attachment of pearls?). Soldered to this is a twisted smooth
wire and then a base ring.
The base is separately made. It is a
circular plate, turned down with a serrate edge visible underneath.
“In this plate, in the inside of the beaker, is a cut circle, under
which is fitted a print of plique-a-jour enamel, with a design of
scrolling foliate stems on a ground of green. […] The enamel is
backed by a separate plate underneath it held by a rim with serrated
edge and a girdle. The rest of the inside of the goblet is plain.”
The lid has a “machicolated rim and a
side stamped with sunk circles, each pierced with a hole”. The side
has two girdles above and below a twisted wire. The lower part of the
lid has scrolling roses and plique-a-jour paneling. On the inside,
these are plain and separated by bands left in the metal. “The top
of the cone is pounced with rays. The finial begins with a ring of
eight flat-ended bosses alternately decorated with applied leaves
(both above and below) and a pounced rosette above. From this rise
eight tiny pointed leaves encircling four great leaves enclosing a
spike on which was probably set a fruitelet or knob in the form of a
precious stone.”
The beaker is compared to a goblet of
silver-gilt in the Berry inventory of 1413, decorated in the same
manner and probably the same technique. Although the beaker is
unmarked and its place of origin a mystery, three countries are
considered most likely places of origin: Germany, Flanders, and
France.
Raising:
Theophilus. On Divers Arts.
Trans. Hawthorne, John G and Smith, Cyril Stanely. New York: Dover
Publications, Inc, 1979.
Page 99: Making
a small chalice
-Before
beginning, find and make center point with compass on balanced sheet
of metal
-Make a square
projection for fixing on foot later
Page 100:
-When silver is
thin enough to bend by hand, draw concentric circles
-inside:
center to halfway
-outside:
halfway to rim
-round hammer
on outside to give depth following circles in a spiral
-medium hammer
on round anvil to make narrow on outside following circles in a
spiral
-When done,
scrape smooth with a file
Page 101
-hammer foot
just like the bowl of goblet was hammered
-no projection
needed
-make sure to
hammer evenly so there is no leaning
-when finished,
anneal and then fill with wax.
-hold foot with
left hand and a thin punch in your right
Page 102
-”seat a boy
next to you with a tiny hammer to strike the punch wherever you put
it.”
-file and
scrape inside and out
-make a square
hold inside the knop, same size as projection
-inside, place
round thick piece of silver with similar hole
-burnish bowl
and foot, inside and out
-rub with cloth
and scraped chalk until shining
-slit
projection in four and place in the knop and ring
-hit with
punch (sounds very much like how a grommet works)
Cellini,
Benvenuto. The Treatises of Benvenuto Cellini on
Goldsmithing and Sculpture.
Trans. Ashbee, C. R. New York: Dover Publications, Inc, 1967.
Page 85: How to
fashion vessels of gold and silver
-trim, plane,
and round edges of oblong plate
-beat into a
rounded shape
-”hammer
from one angle to the other driving the metal well to the center”
to look like a cross and then reverse the process outwards
-diameter
should exceed that of the future vase by three fingers
-balance the
plate to find the center and strike the plate to mark the center on
both sides
-strike a
circle with a compass
-Follow the
circles, hammering “by repeated heating and beating”
-do not lose
the center point – continue beating circle until diameter exceeds
that of future vase
-use compass
again to make concentric circles
Page 86
-”movement of
the hammer should be in the form of a spiral and following the
concentric circles”
-beat and heat
until the silver starts to look like the crown of a hat
-metal should
spread equally
-draw metal
inwards until it is as deep as your model body needs
-use various
stakes and the narrow or broad end of the hammer until equally
bellied
-work out
imperfections as you go
McCreight, Tim.
The Complete Metalsmith. Worcester, Massachusetts: Davis
Publications, Inc, 1991.
Page 58:
Stretching and Sinking
-stretching is
when sheet of metal is forged against a flat surface like an anvil
-as tension
increases between hammered spaces and unhammered spaces, the metal
domes
-advantages:
thick edge, rapid progress, overall size stays the same
-disadvantages:
depth is limited by hammer access
-cut a disk:
diameter + ½ height
-use 20-16
gauge stock
-make
concentric circles using a compass to use as guidelines
-sink metal
into a sinking block using a ball faced hammer or mallet
-progress from
the inside out
-once at a
desired depth, bouge(?) the form over a mushroom stake
-sinking blocks
are made of wood, using the end grain
Page 60: Raising
-an ancient
technique needing only metal, a hammer, and a form to bend the metal
on
-diameter of
the starting disk is the sum of the widest and tallest measurements
-find the
center on the sheet, draw the right size circle, and cut it out
-file and
burnish the edges and then anneal
-if vessel
needs a flat bottom, leave the bottom alone. Sink, stretch, or crimp
to preference
-progress from
the base to the edge is called a course: concentric circles a half
inch apart
-if edge
flares too much, raise a course or two at mid-height
Page 61:
-as raising
continues, top edge will thicken
-exaggerate by
tapping edge with cross peen
-planish once
form is complete
-planish lower
half if, midway, stakes will no longer reach inside.
-straightness
of a form is checked by a surface gauge or with pencil
-trim top and
file if necessary
-to planish,
overlap blows and don't hurry
-planishing
works best if hammer and stakes/anvils have a mirror finish
-any smooth
faced hammer will do
-12-16oz
hammer for quick work, 3-6 oz hammer for finalizing
Soldering:
Theophilus. On Divers Arts.
Trans. Hawthorne, John G and Smith, Cyril Stanely. New York: Dover
Publications,
Inc, 1979.
Page 106:
Casting the handle for the chalice
-with a file
and gravers, fit handles to the bowl in their proper place
-make two
slots, one above and one below for underlying joints
-fit broad pins
into slots on each side of bowl
-fasten pins on
the inside of the bowl and solder
Page 107:
Soldering silver
-melt silver
and copper and file into filings once hardened again
-put filings
into quills
-grind fired
argol in a pot with water and salt until “thick as lees”
-spread liquid
on pins (inside and out) with wooden lath and cover with fillings
-let dry and
reapply more thickly
-put in fire
until solder melts – wash once cold
-may need to
apply many layers
-when firm,
file and scrape smooth so the solder is not apparent
Cellini,
Benvenuto. The Treatises of Benvenuto Cellini on
Goldsmithing and Sculpture.
Trans. Ashbee, C. R. New York: Dover Publications, Inc, 1967.
Page 93: Of
figures made in silver
-a solder
composed of one eighth part of an ounce of copper to one of silver
-fix tubes to
the bellows to blow from below the bed of coals
-when the work
is aglow, blow the bellows gradually to make the solder run
-use
borax...somewhere... Stupid Cellini
-if you need
more, use water and a tallow candle to make an ointment and place
more solder
Page 94
-if you
sprinkle ash instead of water to add fresh solder over the imperfect
solder
McCreight, Tim.
The Complete Metalsmith. Worcester, Massachusetts: Davis
Publications, Inc, 1991.
Page 70:
Soldering
-solder
introduces an alloy that can flow into spaces of expanded metal when
heated
-soft solder is
from surface to surface and can not be filed flush, but melts at a
third the temperature of other solders
-the amount of
zinc in silver solder controls the melting point
-zinc vaporizes
when heated
-each time you
heat solder it raises the melting point
-burning out
the zinc will leave pitted seams
Page 71:
Soldering Process
-for a good
fit: check for gaps by holding work up to the light
-no grease,
finger oils, tape, pickle, buffing compound, pencil marks, etc
-flux is needed
for oxygen absorption
-equal heating
on all soldered pieces for best results
-solder flows
towards heat – it can be drawn -into- a seam via torch position
-use just the
right amount so as not to have to remove excess later
-if soldering
something enclosed, leave room for steam vents
-metal
temperatures are best seen in dimly lit areas
Page 72: Torches
and Blocks
-different
types of torches can be used (I have a canister type on loan)
-Different
types of soldering blocks can be used
-charcoal: can
imbed the work but is expensive and messy
-fire brick (I
have these!): soft, inexpensive, safe but will crumble when a lot of
flux is used
-coiled
asbestos: flat and relatively soft but respiratory badness – avoid
-ceramic &
synthetics: heat sinks and disagreeable fumes when first heated
-wire nest &
pumice: very good for annealing when you don't need flat surfaces
-take care of
build up of flux glass
-apply flux in
fingers instead of on block
-rub blocks
together or sand: wear a respirator!
Page 73: Flux
-fluxes protect
the metal from oxidation by being an oxygen magnet
-as oxygen
combines with the flux and diminishes the protection, seen as a blue
or green tint
-borax: a
mineral, used in paste form with water
-handy flux:
borax based compound, leaves a tough glassy skin
-battern's:
flouride based compound, self pickling, not as oxygen absorbing
-boric acid &
alcohol: add the acid to the alcohol until a thin paste, dip work
into solution
-prips flux:
piece is dipped and then warmed till dry, several applications
recommended, waterproof
-cupronil:
handy for repair work, preserves finish through heating
-hydrogen
peroxide: sparex, peroxide, water – pickle first in sparex,
exposure to sunlight weakens solution
Page 74:
Soldering Methods
-chip: puts on
correct amount of solder, serves as heat indicator
-sweat: more
control, out of sight, directs solder flow
-probe: good
for difficult solder placement, efficient, good for production work
-wire:
advantage of probe without needing to cut solder, control is
important
-mud: used in
commercial assembly, good for filigree, flux can splatter
Page 75: Pickle
-strong
chemical bath to dissolve oxidation and flux residue on the surface
of the metal
-always add
acid to water, wear PPEs, wash hands, keep baking soda close for
spills
-pickle absorbs
copper ions
-plating can
occur if not careful
-introducing
steel will deactivate the pickle
-solutions:
ferrous: sparex #1, non-ferrous: sparex #2, sterling: water/sulfuric,
gold: nitric, water
-best at 80
degrees, do not boil
-flame types
-neutral:
sharp point, gentle hiss, medium blue
-reducing:
bushy, deep blue, pulsing, best for soldering
-oxidizing:
thin cone, angry hiss, pale lavender, not good for soldering
Lost wax:
Theophilus. On Divers Arts.
Trans. Hawthorne, John G and Smith, Cyril Stanely. New York: Dover
Publications,
Inc, 1979.
Page 105:
Casting the handles for the chalice
-shape handles
of wax and carve figures on them
Page 106
-on the top of
each handle, place a small bit of wax – rounded at a slight taper
and the length of your little finger
-called “the
gate” and should be “soldered” on with a hot iron
-vigorously
knead clay and carefully cover each handle
-fill all
holes of the carving
-when dry,
cover again except the top of the gate
-when dry
again, do it a third time
-put mold near
coals and, once heated, pour out wax
-put molds in
fire, turned downwards and leave until red hot
-immediately
melt silver and add spanish brass
-stand up molds
correctly and pour in the silver
Cellini,
Benvenuto. The Treatises of Benvenuto Cellini on
Goldsmithing and Sculpture.
Trans. Ashbee, C. R. New York: Dover Publications, Inc, 1967.
Page 87: How to
fashion vessels of gold and silver
-fashion wax
into whatever design you wish for handle or lip
-dry and sift
earth an mix it with fine cloth shearings and cows dung sifted
-pound tripoli
very fine and make into a pigment
-streak over
the wax ornamentation
-also streak
over the inlet and vent holes
-let it dry
before coating with the clay to the thickness of a knife's back
-apply coats in
this manner until a finger thick
-bind it all
around with iron bands
-more coats of
clay mixed with more cloth shearings
-holding vent
holes downwards, melt out wax
Page 88
-remove from
where it attached to the vase and fill that area with the clay
-bind with more
iron bands
-coat with
tripoli mixture
-fire in a
brick furnace until dry using charcoal
-place mold
into a large receptacle full of sand that is moist but not wet
-when silver is
melted, add finely powdered tartar to keep it fresh
-take a piece
of linen, folded in four and soaked in olive oil, and place over the
tartar that covers the silver
-the rag keeps
the silver warm and keeps bits of coal from falling into the mold
Page 89: Another
method
-mix brick dust
and gesso dust with cold water into a paste
-using a hog
sable, paint over the wax model
-put it all on
at once: after one coat you can layer the thickened gesso on with a
spoon
-bind with fine
iron wire weaving it all around
-cake the mold
with thickened gesso that wasn't sifted moistened with water
-let the gesso
dry in the sun or a warm smoky corner until all moisture is gone
-put over a
slow fire to melt wax
-this method is
quicker than the previous
Page 90: A third
method
-cut wax models
into small pieces and powder and clay them and put in troughs
-make lead
castings from the molds
-clean the lead
castings and work them up to cast them in silver in the same troughs
-this method
can be used many more times than a single casting
Vasari,
Giorgio. Vasari on Technique.
Trans. Maclehose, Louisa S. New York: Dover Pulications, Inc, 1960.
Page 161: The
fire-resisting envelope applied over the wax
-using
moistened ash, cover the figure with a pain brush until concealed
-mix together
fine earth, horse dung, and hair
Page 162
-apply a thin
layer carefully and allow it to dry
-continue
applying thin layers and allowing them to dry until the thickness of
half a span
-gird irons
around mold
-make vents
that issue upwards
-apply heat to
the mold, equally, until all wax has melted out
Page 163
-if you weigh
the wax going in, you can know it is all out of the mold by weighing
it after melting
-no wax = sharp
and beautiful
-wax left
behind = ruin the whole cast
-put the mold
underground and allow for channels to let the bronze flow through
-saw off the
surplus to ensure sharpness
-for every
pound of wax, use ten pounds of metal
-two thirds
copper, one third brass according to Italian rules
McCreight, Tim.
The Complete Metalsmith. Worcester, Massachusetts: Davis
Publications, Inc, 1991.
Page 88: Lost
Wax Process
-most casting
uses the lost wax process developed in ancient egypt
-”When the
metalsmiths of ancient cultures first developd this technique they
made models of beeswax and coated them with layers of clay. The
outer layers were reinforced with straw or linen and the dried
assembly was set into an oven to harden. Simultaneously the wax was
burned away, leaving a cavity into which molten metal was poured.
The clay shell was broken away to retrieve the finished casting.”
Hence the term – lost wax.
-make a model
of wax and mount it on a sprue
-mount the
sprue on a base that fits in a 'flask'
-make an
'investment' free of bubbles, and creamy in conistenc and pour into
flask.
-dry -then-
heat the investment
-while still
warm, pour metal into the mold
-place mold in
water after only brief cooling to release the casting
Gilding:
Theophilus. On Divers Arts.
Trans. Hawthorne, John G and Smith, Cyril Stanely. New York: Dover
Publications,
Inc, 1979.
Page 113:
Amalgamating and gilding the handles
-take ground
argol and salt and put in a large earthenware dish
-pour in water
and newly milled gold and a little mercury
-put on coals
and stir with a stick
-have at the
ready four large hog bristle brushes bound with iron
-two clean
ones to wash the gold and silver
-one wet, one
dry, for the gilding
-Dip a linen
cloth in the hot mixture and rub all over handles – amalgamating
them
-heat over the
coals and rub them with a brush wet in the same mixture
-continue
heating and rubbing until engravings become white because of the
mercury
-this sounds
incredibly dangerous >_<
-in places you
can't reach, rub with copper gilding tool and thing stick
-on a gilding
platter, cut gilding material into tiny pieces
-spread evenly
with wet bristles
-pick up piece
with tongs with tips wrapped in cloth and put back on the coals
Page 114
-once hot,
spread more gold material with the brush until it adheres all over
-do this a
second time and a third time
-when the gold
begins to dry the third time rub it carefully with a dry brush and
heat it again
-rub until it
turns pale
-if a blemish
appears, put on more amalgam evenly
Cellini,
Benvenuto. The Treatises of Benvenuto Cellini on
Goldsmithing and Sculpture.
Trans. Ashbee, C. R. New York: Dover Publications, Inc, 1967.
Page 95: Of
figures made in silver
-When figure is
cool, scrub with blanching solution
-tartar, salt,
water, and I hate you Cellini. Where did you describe this before?
-scrub until
figure turns white with huge hog sable brushes
-put figure in
water to wash off solution
-dry figure
-gild the
figure... but I wont tell you how, just that it was difficult and
looked beautiful after
Enamel:
Theophilus. On Divers Arts.
Trans. Hawthorne, John G and Smith, Cyril Stanely. New York: Dover
Publications,
Inc, 1979.
Page 126:
Setting gems and pearls
-have a flat
piece of thin gold for each setting where enamels will go
-once fitted,
take them out and cut up strips of somewhat thicker gold and bend
them around the strips
-this becomes
the border for the enamel
-using the same
thickness gold strips, bend and shape designs for the enamel
-arrange pieces
in proper place, secure with moistened flour over coals
-solder the
thin gold 2-3 times until firmly adhered
-melt samples
of each color glass to make sure they will all melt well
-Once red hot,
put in a copper pot containing water to immediately burst into
fragments
-wash fragments
and put in clean shell covered with clean cloth
-place gold
plaque on a board and, using a quill, draw up moist glass color
-fill in gold
design with as much glass as desired
-fill the
plaque completely with color
-put plaque on
flat thin iron tray with a short handle
-cover with
another piece of iron, concave like a bowl and perforated with holes
-heap charcoal
on top and burn strongly
-blow with
bellows until holes are red hot
-using a whole
wing of a goose, fan the coals
-wait half an
hour to uncover it gradually
-wait until
holes grow black inside and lift tray out
-put aside
until completely cold
-take out
enamel and wash it
-fill again and
melt as before
-continue until
evenly filled
Cellini,
Benvenuto. The Treatises of Benvenuto Cellini on
Goldsmithing and Sculpture.
Trans. Ashbee, C. R. New York: Dover Publications, Inc, 1967.
Page 15:
Concerning the art of enameling
-make a plate
of silver or gold the size and shape of your work
-create a
mixture of ground resin, brick, and wax
-using a
compass, outline your design
-using a
graver, chisel out the design
-a bas-relief
has to be about the depth of two ordinary sheets of paper
Page 16
-red enamel
does not stick to silver
-I will not
tell how enamels are made.. because I am self righteous and pompous
Page 17
-enameling is
much the same as painting
-make sure
enamel is fine ground
Page 18
-when enamels
are washed and prepared, place in sealed jars to keep them fresh
-fresh water
will spoil them
-take a clean
piece of paper and chew it
-Cellini has
no teeth and couldn't do this
-wash out the
paper putty and squeeze dry to use as a sponge for the enamel
Page 19
-be careful
painting on the enamels
-once the first
layer is on, place piece on an iron plate in a furnace
-once enamel
begins to run, quickly pull it out of the fire
-once cool,
apply second coat and so on until evenly filled
Vasari,
Giorgio. Vasari on Technique.
Trans. Maclehose, Louisa S. New York: Dover Pulications, Inc, 1960.
Page 112:
Vasari's description of enamel work
-if glass is
kept transparent, stained glass window effects are obtained
-similar
effects are found in smaller scaled with plique a jour or cloisonne
enamel
-transparent
pastes are fused into small cells on metal plates
-old examples
are very rare due to fragility
Page 113
-the oldest
know enamels were different colors separated by ridges of metal which
gave lines of design
-pastes that
were used were opaque and completely covered over the metal they were
laid on
-transparent
vitreous pastes fused over a metal ground chased in low relief lets
light show through
-transparent
enamels are also arranged in apertures so as to show by transmitted
light
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Further research used:
Maskell, Alfred. Russian Art and Art
Objects in Russia. Henrietta
Street: Chapman and Hall, 1884.
The
Cooper Museum. Enamel, An Historic Survey to the Present
Day. The Cooper Union Museum
for the Arts of Decoration: 1954.
Labarte,
Jules. Arts of the Middle Ages and Renaissance.
London: John Murray, 1855.
