§ 76 Of the Nature of Painting
A painting, then, is a plane covered with patches of colour on the surface of wood, wall, or canvas filling up the outlines spoken of above, which, by virtue of a good design of encompassing lines, surround the figure.188 If the painter treat his flat surface with right judgement, keeping the centre light and the edges and the background dark and medium colour between the light and dark in the intermediate spaces, the result of the combination of these three fields of colour will be that everything between the one outline and the other stands out and appears round and in relief. It is indeed true that these three shades cannot suffice for every object treated in detail, therefore it is necessary to divide every shade at least into two half shades, making of the light two half tints, and of the dark two lighter, and of the medium two other half tints which incline one to the lighter and the other to the darker side. When these tints, being of one colour only whatever it may be, are gradated, we see a transition beginning with the light, and then the less light, and then a little darker, so that little by little we find the pure black. Having then made the mixtures, that is, these colours mixed together, and wishing to work with oil or tempera or in fresco, we proceed to fill in the outlines putting in their proper place the lights and darks, the half tints and the lowered tones of the half tints and the lights. I mean those tints mixed from the three first, light, medium and dark, which lights and medium tints and darks and lower tones are copied from the cartoon or other design which is made for any work before we begin to put it into execution. It is necessary that the design be carried out with good arrangement, firm drawing, and judgement and invention, seeing that the composition in a picture is not other than the parcelling out of the places where the figures come, so that the spaces be not unshapely but in accordance with the judgement of the eye, while the field is in one place well covered and in another void. All this is the result of drawing and of having copied figures from the life, or from models of figures made to represent anything one wishes to make. Design cannot have a good origin if it have not come from continual practice in copying natural objects, and from the study of pictures by excellent masters and of ancient statues in relief, as has been said many times. But above all, the best thing is to draw men and women from the nude and thus fix in the memory by constant exercise the muscles of the torso, back, legs, arms, and knees, with the bones underneath. Then one may be sure that through much study attitudes in any position can be drawn by help of the imagination without one’s having the living forms in view. Again having seen human bodies dissected one knows how the bones lie, and the muscles and sinews, and all the order and conditions of anatomy, so that it is possible with greater security and more correctness to place the limbs and arrange the muscles of the body in the figures we draw. And those who have this knowledge will certainly draw the outlines of the figures perfectly, and these, when drawn as they ought to be, show a pleasing grace and beautiful style.
He who studies good painting and sculpture, and at the same time sees and understands the life, must necessarily have acquired a good method in art. Hence springs the invention which groups figures in fours, sixes, tens, twenties, in such a manner as to represent battles and other great subjects of art. This invention demands an innate propriety springing out of harmony and obedience; thus if a figure move to greet another, the figure saluted having to respond should not turn away. As with this example, so it is with all the rest. The subject may offer many varied motives different one from another, but the motives chosen must always bear relation to the work in hand, and to what the artist is in process of representing. He ought to distinguish between different movements and characteristics, making the women with a sweet and beautiful air and also the youths, but the old always grave of aspect, and especially the priests and persons in authority. He must always take care however, that everything is in relation to the work as a whole; so that when the picture is looked at, one can recognize in it a harmonious unity, wherein the passions strike terror, and the pleasing effects shed sweetness, representing directly the intention of the painter, and not the things he had no thought of. It is requisite therefore, for this purpose, that he form the figures which have to be spirited with movement and vigour, and that he make those which are distant to retire from the principal figures by means of shade and colour that gradually and softly become lower in tone. Thus the art will always be associated with the grace of naturalness and of delicate charm of colour, and the work be brought to perfection not with the stress of cruel suffering, so that men who look at it have to endure pain on account of the suffering which they see has been borne by the artist in his work, but rather with rejoicing at his good fortune in that his hand has received from heaven the lightness of movement which shows his painting to be worked out with study and toil certainly, but not with drudgery; so will it be that the figures, every one in its place, will not appear dead to him who observes them, but alive and true. Let painters avoid crudities, let it be their endeavour that the things they are always producing shall not seem painted, but show themselves alive and starting out of the canvas. This is the secret of sound design and the true method recognized by him who has painted as belonging to the pictures that are known and judged to be good.