On mixtures.

Take the branching, whether natural or artificial, and coat it once, and then fix it upon a plate of copper so that it does not bend. This done, coat it again with as many coats as you please, which should be very thin, and each time you must let them dry well. After you have coated it in your fashion, you will give thicker and thinner layers of fixed white and transparent colours, and likewise of fixed black and transparent white, and of fixed yellow and transparent yellow made of saffron or of turmeric dissolved with vinegar and then distilled in an alembic — not in an alembic but through felt — and partly with other fixed or transparent colours; and fill the last spaces with fixed white, and so let it dry well, once everything has been brought to one level. Then smooth it with oil and sand, and then with oil and tripoli; then have it sawn into little tablets as thick as a bookboard, and have them cleaned and polished, and then varnished as thinly as you can, and clean off the excess with the hands; often clean these with the edge of a knife so that on the surface no mark of the rubbing of the hands can be seen; and do this six or eight times, and it will not take long, for everything will be done in two or three days, in summer or in winter in the wind, and thus it will seem to be of glass. But remember, if you have them sawn, to coat their surface two or three times with your mixture, so that the materials do not show their dryness and roughness. And if you wish to make large paternoster beads of it, turn such material on a lathe, then polish and coat its surface two or three times as above, and then varnish.

Brazilwood and saffron make cornelian, or else turmeric or celandine. Fig-milk makes chalcedony; walnut husk or soot makes agate. No simple black or white was ever transparent.