§ 84 How to Prime the Panel or Canvas
I must now explain how to set about the work. When the artist wishes to begin, that is, after he has laid the gesso on the panels or framed canvases and smoothed it, he spreads over this with a sponge four or five coats of the smoothest size, and proceeds to grind the colours with walnut or linseed oil, though walnut oil is better because it yellows less with time. When they are ground with these oils, which is their tempera (medium), nothing else is needed so far as the colours are concerned, but to lay them on with a brush. But first there must be made a composition of pigments which possess seccative qualities as white lead, dryers, and earth such as is used for bells,214 all thoroughly well mixed together and of one tint, and when the size is dry this must be plastered over the panel and then beaten with the palm of the hand, so that it becomes evenly united and spread all over, and this many call the ‘imprimatura’ (priming).