76 Composition to put on Skins? Paper? to Linen „ 
invention of a composition to put on all sorts of skins, pa- 
per, or linen, for the use of drawing or writing on with 
pen and ink, or pencil, and rubbing clean off again, and 
to form it into a memorandum book, distinguished by put- 
ting the name of each day of the w eek on the top of each 
leaf of the book, and for other uses and purposes, is to be 
performed in manner following; that is to say, take either 
vellum, parchment, very fine cloth, or paper, and stretch 
it in a frame as tight as possible. Then take twelve 
pounds of w hite lead, and pound it very line ; add there- 
to one third part of the best plaister of Paris, and one- 
fourth part of the best stone lime ; pound them well, mix 
them well together, and grind them very line with water. 
Then take a new glazed vessel, and dissolve six or seven 
pounds of the best double size, over a lire, and mix the 
above ingredients in this, till it is of such a consistence as 
to lay on with a brush. Then lay three or four layers on 
the skin or cloth, as smooth as possible ; observing that 
the skin is dry each time, before a second layer is put 
on. Then take the best nut or linseed oil, and to every 
pound of this oil add four ounces of the best white var- 
nish, and mix them well together. Then put on three or 
four layers of this oil, thus prepared, each time exposing 
it to the air till it is thoroughly dry : this is for the white 
sort. For a brown or yellow, add to every pound of the 
above, three or four ounces of the best stone oker, or or- 
piment, or Dutch pink, and three or four ounces of li- 
tharge. These must be well ground with very old lin- 
seed oil, and laid on, as smooth as possible, ten or twelve 
times ; exposing it each time to the air, to be thoroughly 
dry, before a second layer is put on: observe you do not 
put it where any dust or dirt can fall upon it. It may 
be, by the same process, altered to any colour : as for in- 
stance ; to a red, by tincturing it with vermilion, or the 
like; to a blue, Prussian blue ; and for a black, by pound- 
