Tracing a history on glass
If you want to trace a history in intaglio on glass, you can do so in different ways. Place your glass pane on, as thin as possible, over the printed history, & having cleaned the glass well with lye & ashes so that it is not at all greasy, trace over the lines visible to you with oily black or scales black with a pinceau, if you want to paint with colors in the manner of glaziers, who spread a wash of scales black all over their glass pane & then scratch & uncover what they want to coat with color, leaving that which is necessary for shading. But if you want to make gilt histories on glass with a background of colors, which imitates the basse—taille of goldsmiths, gild the whole glass pane with gum water or garlic juice or fig—tree milk. Then moisten your printed history with two wet linen cloths & lay it down on the gilt glass. Then with a pin mounted on a small stick, follow the lines of your history as if you wished to pounce it, & thus you shall vividly trace it on the gilding of the glass. & next you shall uncover the background & what needs to be empty with a quite pointy steel awl, & and neatly follow once more the lines & accomplish your work & fashion your faces & flesh tones in pounded silver; then fill the background with azur d’esmail or verdigris or fine laque platte, tempered with clear turpentine, mixed with a little larme de mastic if you want the colors to be more unified & not to run. Next, apply on the back of the glass & over the colors a white tin sheet. And once this is dry, you can cover the tin sheet of with color to hide your secret. The tin sheet gives light to the colors. Thus you will be able to paint without being
being at all expert in painting. If your glass pane is bulging as if taken from the belly of a jar, it will show better. When you apply your turpentine colors to your glass panes, first place them on a hot tile &, once they are hot, spread your colors & leave it a while on the tile, then lay down your tin sheet.