A Treatise on Painting

by da Vinci Leonardo

The painter ought to know, that if any white object is placed between two walls, one of which is also white, and the other black, there will be found between the shady side of that object and the light side, a similar proportion to that of the two walls; and if that object be blue, the effect will be the same. Having therefore to paint this object, take some black, similar to that of the wall from which the reflexes come; and to proceed by a certain and scientific method, do as follows. When you paint the wall, take a small spoon to measure exactly the quantity of colour you mean to employ in mixing your tints; for instance, if you have put in the shading of this wall three spoonfuls of pure black, and one of white, you have, without any doubt, a mixture of a certain and precise quality. Now having painted one of the walls white, and the other dark, if you mean to place a blue object between them with shades suitable to that colour, place first on your pallet the light blue, such as you mean it to be, without any mixture of shade, and it will do for the lightest part of your object. After which take three spoonfuls of black, and one of this light blue, for your darkest shades. Then observe whether your object be round or square: if it be square, these two extreme tints of light and shade will be close to each other, cutting sharply at the angle; but if it be round, draw lines from the extremities of the walls to the centre of the object, and put the darkest shade between equal angles, where the lines intersect upon the superficies of it; then begin to make them lighter and lighter gradually to the point N O, lessening the strength of the shadows as much as that place participates of the light A D, and mixing that colour with the darkest shade A B, in the same proportion.

Chap. CCXLVIII.—General Remarks on Colours.

Blue and green are not simple colours in their nature, for blue is composed of light and darkness; such is the azure of the sky, viz. perfect black and perfect white. Green is composed of a simple and a mixed colour, being produced by blue and yellow.

Any object seen in a mirror, will participate of the colour of that body which serves as a mirror; and the mirror in its turn is tinged in part by the colour of the object it represents; they partake more or less of each other as the colour of the object seen is more or less strong than the colour of the mirror. That object will appear of the strongest and most lively colour in the mirror, which has the most affinity to the colour of the mirror itself.

Of coloured bodies, the purest white will be seen at the greatest distance, therefore the darker the colour, the less it will bear distance.

Of different bodies equal in whiteness, and in distance from the eye, that which is surrounded by the greatest darkness will appear the whitest; and on the contrary, that shadow will appear the darkest that has the brightest white round it.

Of different colours, equally perfect, that will appear most excellent, which is seen near its direct contrary. A pale colour against red, a black upon white (though neither the one nor the other are colours), blue near a yellow; green near red; because each colour is more distinctly seen, when opposed to its contrary, than to any other similar to it.