Figure 3. Rome, Biblioteca Casanatense,
MS 1793, fo l. 17r.
42[30] To make gum water for paints. Take of the white gum Arabic, the quantity
you need and put it in a beaker. Next take clear water and put it in this
beaker, so much that it covers the gum about two fingers wide. Place it in
the sun. If there is no sun, put it near the fire and let it stand there fo r three
or fo ur hours, until the gum dissolves. Then take it from the fire, and let it
stand fo r two days, but {16r} make sure that you stir it every fo ur hours.
Next sieve it through a cloth and cover it until you will work with it. This
IS proven.[31] To make egg medium to temper the colors. Take as much white of egg as
you want and put it in a very clean pot. Then take fo ur sponges bound
together at the top and knead with both hands so that the white of eggs
completely turns into such a froth that it will not even fall out if you turn
the pot upside down. Let it stand from the morning until the evening until
it settles and then put it in a bottle. And put some camphor in this bottle so
that, not even after a year, will it go bad.[32] To make a watercolor like gold. Take this previously described glair and put
a little bit of saffron in it; and if you put in more yellow it will all be like
gold.[33] To grind and clean vermilion for writing and miniature painting. Take as much
vermilion as you think you need, grind it very fine with water on the por
phyry stone. Then let it dry on the stone. Then grind it very fine fo r the
second time. Next put it in a glass horn and temper it with the aforesaid
glair and let it stand fo r three or fo ur hours until the vermilion has settled
on the bottom. Then carefully decant the supernatant liquid and replace it
fo r new glair. And keep on doing this fo r two or three times. Thereafter write
with this on your paper. When you think it is not shiny enough, make the
letters you want, large or small, let them dry and then lightly lay with the
brush some of the previously described yellow on it and it will be very shiny
(26).[34] To make green for writing and miniature painting. Take purple lilies and pick
only the petals of these. Pound them and take of the juice. Yo u should know
that this juice is of a purple color. When you add a bit of roche alum, that
is, to a beaker of juice about a chestnut of well pulverized alum, it will turn
blue. Then take pieces of linen cloth and put them to soak very well in this
juice. Then lay it [the cloth] on the grid [to dry], and then it must be soaked
another time so that it will better take on the color. And in between you let
it dry on the grid.[35] To make blue clothlet colors. Take certain flowers, that grow between the
corn, which have five petals and have the color of a purple lily. Take the
petals and rub these leaves in a piece of old linen. Let it dry and if you fe el
that the linen does not take enough color, repeat the treatment fo r a second
time. You can also take the flowers that are called "fior di lebio" or "ibio,"
which also grow between the corn. Pick, when you begin, the flowers that
have a sky blue color and have lots of petals. Pick the petals of these flowers
and squeeze them bit-by-bit with your fingers. Next press them well together,
take out the juice and then soak the linen in it and let it dry on the grid.
{17v} Also: take the petals of the "fior di lino" and crush them and put the
pieces of linen in this juice (27). Let them dry in the same way as described
before and if the pieces of linen would not take up enough color the first
time, dip them in again (28).[36] To make re d clothlets for writing and miniature painting. Take the leaves of
"bietoli," also called "gelosia," and let them dry a bit and then rub these leaves
in a piece of linen cloth and if it does not have enough color fo r you, rub
in more until you think it is right (29, 30). Yo u should know that the leaves
need to be dried because they have a certain humidity of water in them.
Therefore, one lets them dry, which consumes this humidity, so that only the
color remains.Historical Painting Techniques, Materials, and Studio Practice