Sanderson 1658

William Sanderson, Graphice. The use of the Pen and Pensil. Or, the most Excellent Art of Painting: In Two Parts, London [Robert Crofts] 1658.

pp. 81–82

Of Frescoe.

The way of Painting upon walls, to endure weather, the Colours must be ground with lime-water, or milk, or whey, tempered and mix’d in pots, as in Size-colouring. Take the powder of old rubbish stones, mixed with well-burn flint-stones, (or lime) and water; wash out the saltnesse of the lime, by often pouring out the water, and put in fresh, the oftner the better, which makes the plaister of compost: Avoid moist weather, which hath influence upon the walls. (To do the work lasting, strike into the brick of stone-wall, stumps of head-nails, about six inches asunder, which will keep the plaister firm from peeling.).

Then with this compost, plaister the wall a good thicknesse, letting it dry; and your colours prepared ready and mingled, plaister again over the former, the thicknesse of half a crown of silver, very fine and thin, so much as you intend presently to work upon, whilst it wet: Work your colours therein, which will co-operate and corroborate into the plaister, and so dry together as a perfect compost.

Work your painting quick with a free hand, for there cannot be any alteration after the first painting; and therefore make your painting high enough at the first: you may deepen, but not easily heighten.

Avoid Mineral colours; Earth colours are best, as all Oker’s, Brown of Spain, Terre-vert, Spanish-white, and such like.

Your Brushes and Pensills must be long and soft; otherwise they will rake the work, and raise the painting. Your Colours must be full, and flowing from the Brush; your Designe, perfect in the Image, or paper-copy; for in this work, you cannot alter or add upon any colour.