VASARI, in his 'Introduction, to Sculpture', prefixed to his Lives of the Artists, 1550:
About the purpose of small models: 'When sculptors wish to work on a marble statue they usually make first what they call 'a model' for it, which is a guide-pattern (esempio), about half a braccio high (a little under 12 inches), sometimes less or more, just as it suits them; and they make it in clay, or wax, or stucco. Such a model shows, in accordance with the dimensions of the block quarried for the statue, the attitude and the proportions of the figure.'
About small wax models: 'In order to make the wax softer, a little tallow, and turpentine, and black pitch are put into it. Of these ingredients it is the tallow which makes the wax more supple; the turpentine makes it more tenacious; and the pitch gives it a black hue and a certain firmness: after the model has been made and left to stand it becomes hard. If one wants to make the wax a different colour, it can easily be done by putting into it red earth, or red lead, or vermilion. The wax will then assume a peachy colour or some other reddish tint. One can also make it green, by adding verdigris, ... or white, by adding powdered lead-white.'
About armatures: 'To make a wax model to support itself, one can insert an armature of wood or iron; the artist can make his choice between the two; but he can omit the armature completely.'
'If, on the other hand, he wants to make his model in clay, he works exactly as with wax, but there will be no armature of wood or iron because this would cause the clay to crack or split. To avoid cracking, the clay model has to be kept covered with a wet cloth until it is finished.' The duke (Cosimo) has a statue ten feet high, repre- senting Victory with a captive. He has, besides, a group of four captives, merely roughhewn, that show how Michelangelo extracted statues fronT^ the stone.
He would say that tlie artist must have his measuring tools in the eye, rather than in the hand, as it is the eye that judges. He used the same idea in architectural designs.
The method is to take a figure of wax, lay it in a vessel of j water and gradually emerge it, and then note the most salient parts. j Just so, the highest parts were extracted first from the marble.
PerfectionistAlmost every day Michelangelo worked for his amusement on the Pieta which we have mentioned. But at last he broke up the block, either because of defects in the marble, or because the stone was so hard that the chisel often struck sparks, or because he was too severe a judge of his own work and could never be content with anything he did. It is true that few of his mature works were ever completed and that those entirely finished were productions of his youth. Such were the Bacchus, the Pieta; of the Madonna della Febbre [in Saint Peter's], il G-igante [the David], at Florence, and the Christ Risen of the Minerva [Santa Maria sopra Minerva], which are finished to such perfection that a single grain could not be taken from them without injury. Michelangelo often said that, if he were compelled to satisfy himself, he should show little or nothing. The reason is obvious: lie had attained such knowledge in art that the slightest error could not exist without his immediate dis- covery of it. But once it had been seen in public, he would never attempt to correct it, but would begin a new work, for he believed that a similar failure would not happen again. He often declared that this was the reason that the number of his finished works was so small. —