have little rods that enter exactly through its holes, and push them in so far through each hole that each white rod touches the figure in different places; and the part of those rods that remains outside the box, tint black, and make a countermark on the rod and on its hole, so that at will they may be matched. And you will draw the clay figure out of that box, and put in your piece of marble, and remove so much of the marble that all your rods hide up to their mark in the said holes; and, the better to do this, make the whole box able to be raised up, and let the bottom of that box always remain under the marble, and in this way you will be able to remove material with irons with great ease.

[513] To make a painting of everlasting varnish.
Paint your picture upon paper stretched on a frame, well delicate and flat; then give it a good and thick priming of pitch and well-ground brick; then the priming of white lead and giallolino; then colour, and varnish with old, clear and firm oil, and stick it to well-flat glass. But it will be better to make a panel of well-glazed earthenware, well flat, and then over that glaze put the priming of white lead and giallolino; and then colour and varnish, then attach the crystalline glass to that glass with the varnish very clear; but first let that colouring dry well in a dark stove, and then varnish it with walnut oil and amber, or walnut oil thickened in the sun.