Historical Painting Techniques, Materials, and Studio Practice

[1] How to make a gold ground. Take fine, slaked gypsum, as much as the size
of a nut, and grind it with a little bit of clear water. Then take Armenian
bole, as much as a chickpea or a bean, and grind this separately, and also with
water. Having done this, mix them together, take some dissolved glue and
add it. Next have a bit of candy or sugar and some earwax and grind it gently
together. The glue must be so strong that the whole matter sticks a little bit
to the porphyry stone when you grind it. Then you keep it warm above
some hot coals. When you work with it you can add some glue so that it
will be a bit fluid. Let the dissolved glue stand a few days so that it comes
from the fire with better strength. Now you can work with it. When the
work is dry, scrape it until it is smooth. Then wet it with clear water and lay
the gold on it. Press on it when it is dry. If the gold ground would be too
weak for you, distemper it: you can put a bit of glair in the water (4).
[2] To make lines of burnished gold. Take slaked gypsum, grind it with glair and
a bit of honey, some earwax, and a bit of glue. Let it dry [when applied], then
huff on it and lay the gold. Burnish it (5).
[3] To make lines of gold in another way. Take [gum] ammoniac and grind it
without water or anything else. Then take garlic juice and grind it with it.
Next add a little bit of Armenian bole to it. Work with it. When this is done;
huff on it and lay the gold on it (6).
[4] To make the blue clothlets. Take a plant called turnsole, of which you pick
one-by-one the flowers and clustering {llr} berries. Then you put these in
a mortar, according to the quantity you want to make. Crush them and press
the juice out of the aforesaid berries. You put this juice in a glazed bowl and
then you take pieces of cloth that are white and coarse. Then you put these
into the aforementioned bowl [with the juice] and let them soak well in it.
Do this three times, and every time that you take it out of the mentioned
bowl, you let it dry well on a wooden bench. Before you reach this stage,
make sure you find a remote quiet hole in the ground, and urinate much in
it, six days before you come to make the said turnsole. Take straw and make
a screen over the urine and place the cloths above the humidity of this urine.
Thus it will become darker and more beautiful, and let it stand there for at
least twenty days above the aforesaid urine and then the turnsole will have
become beautiful.
You prepare it as follows: Take glair according to the quantity you think this
turnsole needs to have to become deeply colored. When you want to work
with it, take this glair in a shell or some glazed small pot and then take the
turns ole and put some of it in according to the right amount and let it stand
[in the glair] for an hour and then press it out with your finger and the juice
that comes out of the clothlet is the turnsole. With this you can work, using
a little bit at a time (7).
[5] To make a fine ink. If you want to make a fine ink, take one pound of
galls. Break it into smaller pieces and put it in ten pounds of rainwater or
water from the pot. Let it boil in a pot that has not previously been used,
until the volume of this water is reduced to half. Next sieve it and throw out
the substance of the galls and put the water back in after you have washed
the jar. {11 v} Having this done, put in five pounds of the softest white wine
you can find, i.e. replacing the amount of water that has evaporated. Let it
cook and when it starts to boil, put in half a pound of perfectly pulverized
gum Arabic, adding this bit by bit while stirring with an iron cane until the
gum is dissolved. When that is done, take the aforesaid vase from the fire and
then put in half a pound of perfectly pulverized Roman vitriol. Then cover
it, so that no dust can get into it and let it stand for three or fo ur days on a
quiet place, because when you leave it alone it becomes more beautiful and
blacker. Then without forcing it, sieve it through a cloth into a glazed pot.
And if you want this to be right, you sieve it after 15 days three times. Know
that the vitriol loses its quality through smoke, that is why one does not heat
it on the fire. If you cannot find white wine, you may take red wine, which
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