A Treatise on Painting

by da Vinci Leonardo

Although the mixture of colours may be extended to an infinite variety, almost impossible to be described, I will not omit touching slightly upon it, setting down at first a certain number of simple colours to serve as a foundation, and with each of these mixing one of the others; one with one, then two with two, and three with three, proceeding in this manner to the full mixture of all the colors together: then I would begin again, mixing two of these colours with two others, and three with three, four with four, and so on to the end. To these two colours we shall put three; to these three add three more, and then six, increasing always in the same proportion.

I call those simple colours, which are not composed, and cannot be made or supplied by any mixture of other colours. Black and White are not reckoned among colours; the one is the representative of darkness, the other of light: that is, one is a simple privation of light, the other is light itself. Yet I will not omit mentioning them, because there is nothing in painting more useful and necessary; since painting is but an effect produced by lights and shadows, viz. chiaro-scuro. After Black and White come Blue and Yellow, then Green, and Tawny or Umber, and then Purple and Red. These eight colours are all that Nature produces. With these I begin my mixtures, first Black and White, Black and Yellow, Black and Red; then Yellow and Red: but I shall treat more at length of these mixtures in a separate work [52], which will be of great utility, nay very necessary. I shall place this subject between theory and practice.

Chap. CCXXVII.—Of the Colours produced by the Mixture of other Colours, called secondary Colours.

The first of all simple colours is White, though philosophers will not acknowledge either White or Black to be colours; because the first is the cause, or the receiver of colours, the other totally deprived of them. But as painters cannot do without either, we shall place them among the others; and according to this order of things, White will be the first, Yellow the second, Green the third, Blue the fourth, Red the fifth, and Black the sixth. We shall set down White for the representative of light, without which no colour can be seen; Yellow for the earth; Green for water; Blue for air; Red for fire; and Black for total darkness.

If you wish to see by a short process the variety of all the mixed, or composed colours, take some coloured glasses, and, through them, look at all the country round: you will find that the colour of each object will be altered and mixed with the colour of the glass through which it is seen; observe which colour is made better, and which is hurt by the mixture. If the glass be yellow, the colour of the objects may either be improved, or greatly impaired by it. Black and White will be most altered, while Green and Yellow will be meliorated. In the same manner you may go through all the mixtures of colours, which are infinite. Select those which are new and agreeable to the sight; and following the same method you may go on with two glasses, or three, till you have found what will best answer your purpose.

Chap. CCXXVIII.—Of Verdegris.

This green, which is made of copper, though it be mixed with oil, will lose its beauty, if it be not varnished immediately. It not only fades, but, if washed with a sponge and pure water only, it will detach from the ground upon which it is painted, particularly in damp weather; because verdegris is produced by the strength of salts, which easily dissolve in rainy weather, but still more if washed with a wet sponge.

Chap. CCXXIX.—How to increase the Beauty of Verdegris.

If you mix with the Verdegris some Caballine Aloe, it will add to it a great degree of beauty. It would acquire still more from Saffron, if it did not fade. The quality and goodness of this Aloe will be proved by dissolving it in warm Brandy. Supposing the Verdegris has already been used, and the part finished, you may then glaze it thinly with this dissolved Aloe, and it will produce a very fine colour. This Aloe may be ground also in oil by itself, or with the Verdegris, or any other colour, at pleasure.