§ 87 Vasari’s Own Method
Since the experience of many years has taught me how to work in oil on a wall, I have recently, in painting the halls, chambers, and other rooms of Duke Cosimo’s palace,217 followed the method frequently used by me in the past for this sort of work; which method is briefly this. Make the rough cast, over which put the plaster made of lime, pounded brick, and sand, and leave it to dry thoroughly; that done, make a second coating of lime, very finely pounded brick, and the scum from iron works; these three ingredients in equal proportions, bound with white of egg sufficiently beaten and linseed oil, make a very stiff stucco, such as cannot be excelled. But take great care not to neglect the plaster while it is fresh, lest it should crack in many places; indeed it is necessary, if one wish to keep it good, to be ever about it with the trowel or spatula or spoon, whichever we choose to call it, until it be all evenly spread over the surface in the way it has to remain. Then when this plaster is dry and some priming or composition laid over it, the figures and scenes can be perfectly carried out, as the works in the said palace and many others will clearly demonstrate to everyone.