BnF 640 RECIPES
--------------ENAMEL------------
1. General Enameling
<p039v_a1>: Enamel
Enamel takes more readily to copper than to silver, it is true that the cut has to be deep and rough. Azure in body and the red called gules, white enamel and thick green take [to such metals] very well. After applying the enamel, one gilds the cut foliage. Copper is as hard to cut as pure silver or pistolet gold.
<p103v>: Enamels
To well recognize their difference and their true color by candlelight, it is necessary to put the candle behind a crystal mirror, or a glass globe or jar full of water, because this light is like sunlight.
<p116r>:A way to enamel very fine gold rose leaves and others
After you have cast or beaten in gold the thin leaves of a rose or other things, if you want to enamel them, you must solder or braze your fine, gold leaves onto silver strips, which will strengthen them to support the enamel. After the things has been enameled, put the work in aqua fortis, which will eat away the silver and leave all the gold with its enamel. For this, the gold must have been passed…
<p136r_a1”>: Enamelling thin works
Goldsmiths polish the gold leaf using a burin and then they apply the enamel onto it.
2. Enameling Reds
<p104r_a5> Enameling a Carnelian
Soak some wheat flour in white wine, and slop and cover the whole carnelian. Then cook the violet again, then soak it into white wine for one or two hours, then rub it and leave the part you want to keep on it, then lay on some more on top again.
<p124v> Rouge clair enamel
Pure gold does not work well with enamel because the enamel remains yellowish. Alloyed gold, such as that of escu or pistolet coins, works better. The pale color of pure gold makes the enamel seem faded. That is why you must heat it again after being cut to make it reddish so that the enamel will be beautiful, otherwise it will be dull.
A kind of light rouge clair which, scratched with sand, will lose its beauty.
There are some with gold grains in it. And also, good goldsmiths agree that the good one is made with gold.
<p040v_01> Cross of the commanders of Malta
The fine rouge clair which is the background of the white enamel cross is of fine dragon’s blood drops soaked with eau de vie or Indian laque plate, which I believe is made in Flanders, distempered with clear turpentine and mastic drops and applied on a silver leaf, not the one used by painters but a thicker one, which is burnished by the makers of foil backings for gemstones or by goldsmiths, and that gives it its fine brilliance.
<p006r_1>To lay down and set burnished gold and red or green or blue
Ceruse and lead white is not appropriate for polished white nor for burnishing because it is fat, but it is quite good for matte gold, which is made with oil [by] mixing it with yellow ochre and mine and tempering the whole with oil, and this matte gold so applied lasts in the rain as gilded leadworks and similar things [do]. Therefore for burnished gold take some good chalk, quite white, well ground and soaked with distemper glue and with it, make four coats one after the other on the wood. And the last being dry, rub it with horsetail, which is an herb differently named horse tail, to render it well polished. Afterwards, take some fine Armenian bole and some sanguine, as much of one as of the other, [and] also lamb tallow the size of a bean or a pea depending on the quantity of bole and a little bit of willow charcoal or as much as of tallow and half a walnut shell filled with half-burned saffron; some put in a little candi sugar. Grind everything together with water and apply it without gum or glue and let it dry and rub the place that you would like to gild with a piece of white cloth to better unify [it] and when the rubbed place is a little shiny it is a sign that the gold will be well. Having rubbed, wash the place that you want to gild with a clean brush soaked with clear water and promptly apply the gold which you will burnish once dry. And if you want to set some rouge clair and glaze it, grind some Venice lake on the marble with some walnut oil or linseed oil. Once ground mix some turpentine varnish or spike lavender varnish and apply; on gold, [when applied] with the brush, brazilwood and laque ronde fade away. For green, temper verdigris with walnut oil or linseed oil and grind it, then mix in some turpentine varnish and not aspic varnish which is not suitable for verdigris. If you want to glaze with azure it has to be set on burnished silver and take azur d’esmail and without grinding mix it with turpentine varnish and apply.
3. Enameling Blues
<p011r_1>: How to paint azure enamel
This is a secret hardly known to common painters. Some take the finest they can and grind it with some ceruse, which binds it, and then prick with an awl in several places the areas they want to paint with azure enamel, so that the oil soaks into it in drops, not allowing the azure, which alone is heavy, to run. Others lay the painting flat and apply the azure and that can be also soaked. The most important is to grind it well on marble, and before that, to have rinsed it. Some grind it thoroughly with an egg yolk and then rinse it five or six times and apply it not with a paint brush, which would be too soft, but with a brush highly softened and curled, and laying it down thickly as if you were applying it with a trowel, it settles even and flat. I experimented [and found] that grinding azur enamel with egg yolk and then rinsing it in water is good. However it does lose a little vividness when ground. I also rinsed it successively in water and, after letting it stand, I extracted some blue water with a sponge and pressed it into another vessel where it was left to stand, and from the residue I obtained the dust, flower and finest part of the azure without grinding it, which is the best way, because it loses some of its color when ground. Those who make it in Germany compose it like enamel, in large pieces which they pound, pass through several sieves and rinse.
To make azures beautiful, they wash them or soak them in rock water, as they call it, which is water distilled from mines where azure or vert d’azur is found, either distilled naturally through the mountain’s veins or distilled with an alembic from azure or copper mineral stones.
Azure dust is not good for landscapes because it fades with oil. Only true azure holds. Azure enamel cannot be worked if it is too thick. Therefore, try it on your fingernail or your oil [color] palette. If it is sandy, grind it only with egg yolk or, even better, rinse it in clear water and with a sponge extract the colored water after it starts to sink, and in this way you will extract the finest flower, which will be easy to work with.
<p059r_2>: Azure (2, 5, 6, 7)
Azure is more beautiful when on the painting it has soaked up some nut oil with which it has been firstly thinned without any aspic oil. If you want to know whether it is dry, breathe on it and it will not shine and will seem to be very soaked up, otherwise it will shine.
Soaked-with-oil azure d’email leaves it and comes back to its first natural state if you dip it in some water
Colors for small scale works have to be very strongly ground and to be worked with a brush point if you want your work to be very fine
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The varnish is more beautiful on a painting when the color has been completely soaked up
<p061v_3>: Azure enamel with oil (2, 4, 5, 7)
One must choose the finest possible, for if it is coarse one cannot work in oil. And if you cannot find any that is fine enough, you may as well grind it, not with water but with oil, and grind it thick. Then lay it on your palette and mix in some turpentine but not much, to make it bind, and make it as thick as butter or mortar, and then with a large enough brush work it while always twirling the brush. Then, to soften it, make jagged hatching movements with the tip of the brush. The highlights will be made using the same diluted with ceruse, which makes it bind, making it easier to work. I have seen it used thus. It must be very thick, so that you almost need an effort to spread it with your brush. And it will be all the better if you lay down your painting. All these difficulties do not occur when it is very fine and fluid without being crushed, and it doesn’t run.
Azure needs to be applied neatly, which is why it always fades when it is applied over old, already tarnished, azure to mend an old painting. In such cases, it is better to scrape off the old layer and prime again and then apply the azure. It is the same for almost all other colors. Also azure mixed with oil always remains shiny, which is not good for azure because that makes it fade.
<p093v>: Azure
Azure enamel always requires washing because the impurities found in the wastewater would make it fade. It should always be applied twice, at first very thickly, moving the brush so as to lay it first lengthwise and then across. It is better used on canvas, which absorbs it immediately, than on wood. Varnish restores its brightness, because once absorbed it becomes dark. In order to test it, painters bring their palettes to the grocer’s and distemper and mix it with a little white groundin oil, for in this manner the good one appears typically.bright blue, while the bad one is lavender grey. The thinner one is best to work with. It is refined by washing.
------------GEMS-----------
1. Hyacinth
<p101v>:Hyacinth
It is made, like rubies, with gold; but without such intense heat. Rubies need to be heated for a whole day, and if it does not have heat for long enough, you will obtain only reddened varnish.
Always heat up your crucibles.
It is believed that rubified antimony makes hyacinth.
2. Sapphire
<p038r_1>: Sapphire
There are sapphires that we call trellis sapphires, for they are pierced and it is said that a certain king made a certain ornament out of these in a trellis-like form, perhaps similar to the Écrin of Charlemagne, as it is named, in the treasury of Saint Denis, in which the gems are set without foil, so as to enjoy its brightness from both sides, and to show their native quality. I have a white one that seems to be rough and pierced, and is all over spotted with blue. I am of the opinion that these spots are artificial and made of taffre or very clear azure enamel fused on the sapphire. Lime corrodes it as it does on beryl.
<p038r_3>: Sapphire
Stone cutters sometimes choose old pieces of antique glass in church windows, which are much thicker than those of today and have more natural colors. If it is for sapphire, they chose the beautiful blue and from those parts in which there are no grains, if possible. After cutting it into squares with emeril, they cut it in bevel and polish it. In this way, they imitate very beautiful sapphires. The old azure enamel for silver, when close to aquamarine, was very suitable for imitating sapphires, but you cannot find it anymore. Aquamarines are imitated with white glass, but they take it from the bottom of the glass.