This sort of work is delightful. In my time in Rome, that was about
1525, there was a certain master from Perugia, called Lautizio, who
practised nothing else but the making of seals for the bulls of
cardinals. These seals are about the size of a ten-year-old child’s
hand, and they are made in the shape of an almond. The cardinal’s
title is engraved on them, and usually in the form of a rebus, or
allegorically. Lautizio used to get at least 100 scudi for each seal
he made. Now always sticking to my method of describing things from
work I have done with my own hands, I’ll tell you of two that I made
in this branch of my art.
The first was for the Cardinal of Mantua, brother of the Duke. On it
was engraved the ascension of our Lady, with the Twelve Apostles,
for so ran the Cardinal’s title. The other seal, much more richly
figured, was for the Cardinal Ippolito of Ferrara, brother of Duke
Hercules. On this one was engraved St. Ambrose on horseback, with a
whip in his hand chastising the Arians. And as two stories had to be
wrought upon it, for the Cardinal had a twofold title, it was divided
down the middle and the legend of St. John the Baptist preaching in
the desert was engraved on the other part, and both subjects were
wrought with figures. For the Mantua seal I got 200 ducats, for the
Ferrara one, 300.
The seals are made in the following manner. You take a smooth and
polished black stone, and draw thereon the design you want to appear
on the seal; and with black wax, a bit hardened, you fashion whatever
relief you wish the seal ultimately to impress. When this is very
delicately accomplished, you take a little volterrano gesso,[66] or
any other gesso, provided it be very fine—boiled gesso it should be—&
after having moistened your wax by painting it over very lightly with
a fine paint brush and a little clean and pure olive oil, you put
the gesso on your wax. You must mind not to get too much oil on your
wax, for it would then hurt the gesso and prevent it from penetrating
into the finer delicacies of the wax. Before pouring on your gesso
in the liquid state, you must make a little wall or embankment of
fresh clean clay, about two fingers high, all round your seal. As
you pour your gesso on, you guide it about very carefully into all
the interstices of the wax by means of a long-haired brush.[67]
After the gesso is well set, remove it from the wax. This, of course,
will be easily done, as there is no undercutting, for since the work
is ultimately to serve the purpose of a seal, no projections are
permissible. Then you clean out the matrix with a knife, removing any
scum or spoiled surface that may have been made by the gesso on the
inside, and polish it all up all round.
Now there are two ways of casting in silver, both of them are good
and both of them will I describe to you. ’Tis true that one is a
little easier than the other, but as I say, both are good and you may
adopt whichever most wins your fancy. Do not, however, fail to try
both, because it is good for you to learn them, & you will find them
very helpful to you in many ways in other branches of the goldsmith’s
art. The first method was the one employed by Lautanzio, and he, as
I said, was the greatest master in this branch of work whom I ever
knew. He used to take what is called earth for founding in boxes,[68]
the same that all the bronze founders use, and from which they cast
the harness of horses & mules, brass studs, and such-like trappings.
And forasmuch as this clay is known all the world over, I shan’t
bother about describing it, but only say that it is a kind of tufa
earth. By the bye, as I write I am minded of a very rare kind of this
tufa which is found in the bed of the Seine in Paris. While there I
used to take what I wanted from hard by the Sainte Chapelle, which
stands on an island in Paris in the middle of the Seine. It is very
soft, and has the property, quite different from other clays used for
moulding purposes, of not needing to be dried, but when you have made
from it the shape you want, you can pour into it while it is still
moist, your gold, silver, brass, or any other metal. This is a very
rare thing, and I have never heard of it occurring anywhere else in
the world.
Before considering the other kinds of clay that may be used for this
sort of work, it will be best for me to tell you carefully how to
make your gesso model for casting your seal from. After it is well
cleaned with the knife in the way above described, powder it with a
little fine charcoal-dust, or smoke it over with the soot from your
lamp or taper; either will do, and I really needn’t describe this,
because everybody knows how to do it. Then press the model into a
caster’s sand-box of sufficient size to hold it conveniently.
This done, dry well that portion of the mould where the figures come
(that is to say if you are using the Italian, not the Paris clay),
then have ready a little dough[69] in the form of a cake similar
in shape & thickness to what your silver or metal seal is finally
to be, and put this over the figures formed by the gesso and which
will appear in relief, having previously smoked over the mould with
a little candle-smoke. This done, take the second box, fill it with
the same moist earth and when dried set it upon the first. Mind in
so doing that you do not disturb the part already dried where the
figures are.[70] This second half you will easily mould. Then open
the mould, and after taking out the dough-cake, make the mouths and
the two vent holes, beginning at the bottom and going up as high as
the mouth or ingress hole. When both parts are dry, smoke them over
with a little candle-smoke and let them cool, have your silver well
molten and then pour it in. Experience shows that it is better to
pour the silver into cold than into hot matrices.
Now, for the second method, differing considerably from the first,
but, as I have employed both, and the second not only for seals but
for casting all sorts of other things too, I’ll describe it to you
also. When you have from your original wax cast a gesso matrix in the
manner above described, take a little of the same gesso, mix with it
a little pith of horn[71] well dried, a further part of tripoli,[72]
& finally another part of well-powdered pumice stone, and pound these
four parts well up together. Then add as much water to them as shall
give them the consistency of a paste—neither too thick nor too fluid.
Then with a fine brush paint the surface of your seal all round over
the wax projections and into the interstices, with a little olive
oil. Waiting till it is well dried in the way we Florentines call
_verdemezzo_, that is to say neither too dry nor too moist,[73] make
a little wall of clay about two fingers high all round it, and pour
the above mixture into the work and paint it well in and around the
whole of your subject. Pile the mixture up at least two fingers high
and make about four fingers more of it at the upper end on account
of the almond form which is the shape your seal will be, for you
need there greater size for the pouring-in mouth of your silver or
whatever metal you may be using. When the gesso is thoroughly dried,
which will not be till some four hours or so, separate the one piece
of gesso from the other, taking very great care that none of your
design is injured. As you may well imagine, it was much easier to
separate the matrix from the wax in the first method than from the
composition in the second, because in the former it had a firmer
consistency. If some of the arms and heads don’t appear to you to
come out quite a success, and remain stuck in the matrix, you can
remedy that in either of the following ways. You can either pick out
the bits remaining in the mould with a small paint brush, & re-apply
them with a little powdered tripoli, and since your design is in
relief you will easily see the impressions made by it in the mould.
Or, for the other way, you can clean out the mould entirely, paint
it round again and fill it up with the composition in the same way
as before; often if the first turn has not come out well, the second
does.
But pay the greatest possible attention to what I am going to tell
you now. Make a waxen form, almond-shaped, and of the exact size your
seal is to be, hollow it out, and lay it over the surface of your
gesso relief. Then make your little ramparts of earth about this wax,
taking heed to make due provision for the channel of the casting,
which should be of ample length; & here I ought to tell you that the
longer your channel is the better chance your work has of turning out
well. There are no end of little details still to be observed, but
if I were to tell you all of them I might as well begin teaching you
your A B C. So I assume that my readers are people who have mastered
the first principles of the Art. I would remind you, too, that both
the ingress mouth & the vents have to be made of wax & applied to
the wax core. These vents are fixed below, & turn up around the seal
towards the ingress mouth; they must not, however, come in contact
with the latter, because they have to do their own work of drawing
out the air.[74]
This done, bind up your seal with well-tempered iron or copper wire,
and let it bide in the sun, or some place where it can get warm &
well dried. Then put it in your little furnace of tiles and iron
hoops and melt out the wax with such heat as may be needful. Of
course your wax must have been free from all impurities or it would
never melt out properly. And when you have melted it out you make
the fire stronger till your mould is regularly burnt, & the more it
is baked the better your work will be. Then let it cool, and because
the silver adapts[75] itself more readily to the cold than to the
hot mould—cold, mark you, but not moist—when it is well molten pour
it in. But ere you do this, in order that it may not burn,[76]
strew a little borax over it and upon that a handful of well ground
tartar,[77] and you will find this help your work wonderfully. Then
dip the mould in water in order better to separate it from the
silver, and so break it open. This done clean the silver off at the
points where the channel & the vent holes come, and give it a subtle
finish with the file. After this, in order to give the seal its final
touches, you place it on the pitch, and, with your first gesso matrix
before you, work the silver with your punches, gravers and chisels,
touching up and completing your subject now here, now there, figures,
swags, arms, bodies, legs, all alike, accentuating[78] them in the
matrix with your steel tools. To see better how you are getting
on, you may occasionally press in a little black wax, or whatever
colour pleases you better, to gauge the projections. Now note this:
my custom was to cut out the heads, hands and feet of my figures on
small steel punches, and thinking the work came clearer and got a
better result, I struck these punches with dexterous strokes upon
the seal with a hammer into their different places. Also you should
make in a similar manner an alphabet of steel punches, likewise many
other conceits according as taste prompts. When I was in Rome, or
elsewhere, working in this line, I ofttimes amused myself by making
new alphabets, each for its occasion, for they wear out soon, and
I got much credit by my inventiveness. Your letters should be well
formed, & shaped as a broadly cut pen might shape them; the strokes
going up or down with the action of the hand, the letters being
neither too fat and stumpy, nor too long and thin, for both these are
unpleasing to behold, the moderately slim ones are the nicest to look
at.
I ought not to omit telling you that the cardinal’s arms, or whatever
they may be, have to be done on the seals; and these are always
richly ornamented with figure work, and I often used to have for
the handle where-with the seal was attached, some fine beasts, or
as often figures, according to the emblem of the gentleman for whom
the seal was made. You should be careful not to omit these little
complimentary touches because they redound to the honour of the
master & please the patron whom he serves. I made, among others, such
a handle in gold for the Duke of Mantua after I had made the one for
his brother the Cardinal; and in addition to all the care I had put
into the seal itself, I added a little Hercules for the handle, & he
was sitting on his lion’s skin, and had his club in hand. For this
tiny figure I made no end of studies, & it brought me much honour
with the sculptors and painters, and among these was Master Giulio
Romano; some of them made use of the design, too, for other purposes,
and I was well paid for it.
Some artists have gone straight to work at their seals with merely
cutting directly into their silver, and without casting at all, but
pluckily doing their design straight on in the reverse with genuine
knowledge of their art, and using the steel dies of which I told you,
and they succeeded in it, too. I also have done this, but I have
found the casting method more practicable; though both are good, and
can lead to excellent results.
FOOTNOTES:
[66] _Gypsum or plaster from Volterra_ (_the 1568 edition has_
‘_gesso cotto Volterranno_.’)
[67] _Un penelletto alquanto grandicello di vaio_—_what I think in
the English workshop would be called a ‘rigger.’_
[68] _Che si chiama terra da formare nelle staffe._ _It is not a
clay, but as he says, a sand tufa_ (‘_areno di tufo_’) _a volcanic
spongey rock like pumice, and they make cement of it_.
[69] _Pasta di pane crudo._
[70] _The 1568 edition gives a clearer version of this process
than the original codex, which is confusing. I have translated it
as literally as possible, but the following might be read as more
descriptive of the process: The gesso matrix has been pressed into
the sand of the first box, and has made the mould of the relief work
of the seal, the dough is to make the shape of the body. It would
be roughly cut away to clear the figures, and carefully placed over
the part moulded. Then the second box would be put on, and the moist
earth tightly packed in. After this the boxes would be separated and
the dough taken out._
[71] _Midollo di corna._ _See Hoepli’s handbook ‘Oreficeria’ for the
modern process._
[72] _Calcined sulphate of iron._
[73] _Or, as we English would perhaps say, ‘tacky.’_
[74] _This, which is the ordinary cire perdue process, is again
described in Chapter XXII., where Cellini deals with a vase he is
making. The accompanying diagram illustrates it in its application to
seals. The mouth or ingress hole, or what will become the mouth, is
rolled in wax and attached to the top, the two vents are rolled and
attached in a similar way below, but so as not to touch the pattern._
[Illustration: Diagram illustrating the application of the _cire
perdue_ process to seals
V VENT. (_Sfiatatoio_)
M MOUTH OR INGRESS HOLE. (_Bocca_)
A ALMOND-SHAPED SEAL.]
[75] _Segli accosta._
[76] _Riarda_: i.e., _oxidise_.
[77] _Gromma di botte_: _tartrate of potash_.
[78] _Risserando._
[Illustration: Specimens of Cardinals’ Seals]