Cennino Cennini's Recipes for White and Black
How to prepare white:
Take a very white slaked lime (calcia sfiorata); pulverise it, and put it in a little tub for the space of eight days, changing the water every day, and mixing the lime and water well together, in order that it might throw off all unctuous properties (grassezza). Then make it into little cakes, put them on the roof of the house in the sun, and the older these cakes are, the whiter they become. To do it quickly and well, when the cakes are dry, grind them on your slab with water, make them into cakes and dry them again. Do this twice and you will see what a perfect white it becomes. Grind these cakes well, with water. It is good for working in fresco. Without it you can do nothing: you cannot paint flesh, or make tints of other colours, which you need in fresco on walls; and it never needs tempera.
How to prepare black:
Procure a slab of porphyry which is hard and strong, porphyry is best of all. Take another stone, also of porphyry, flat beneath and raised above in the shape of a porringer, of such a form that the hand may be mistress of it and move and guide it at pleasure. Take some of the black porphyry, about the size of a walnut, and with the stone in your hand break the pigment into small pieces. Add clean water from a river, a fountain or a well, and grind it well as long as you please; but know that if you were to grind it for a year, so much blacker would be the colour. Take a flat piece of grained wood, scrape the stone and collect the colour. Another black is made of the young shoots of the vine, which are burnt and then thrown into water, and quenched and then ground. Another black is made of the shells of almonds, or of peach stones. Another black is made of the smoke of a linseed oil lamp, gathered on the bottom of a baking-dish: it does not require grinding, because it is already a very fine powder.
Adapted from The Book of Art, 1437 (Italy)
And with that I'm off to meet my brother in Chicago to spend a few days soaking up art and music, eating amazing food, and generally recalibrating my internal systems. We will also be renting a car and driving over to Holland, Michigan, on Friday to join the rest of our family in celebrating my Grandma's 95th birthday. I'll report back from the other side.