The Artist's Assistant, In the Study and Practice of Mechanical Sciences: Calculated for the Improvement of Genius. Illustrated with Copper-Plates (Birmingham, [ca. 1785])

THE ARTIST'S ASSISTANT. u5

till the pafte between the cloth and paper was Ef-
ficiently wet to admit of feparation.

When painters want to make a very correct copy
of a picture they generally make ufe of a tiffanv,
or black gauze, drained tight on a frame, which
they lav fiat on the fubject to be imitated, and with
a piece of fketching chalk, trace all the outlines on
the tiffany. They then lay the canvas to be painted
on, flat upon the floor, placing the tiffany with
the chalked lines upon it, and with an handkerchief
brufh the whole over: this prefents the exacl out-
lines of the picture on the canvas. The craycu
painter may alfo make ufe of this method, when
the fubjeft of his imitation is in oils, but in copy-
ing a crayon picture, he muft have recourfe to the
following method, on account of the glafs:

The pifture being placed upon the efel. let the.out-
lines be drawn on the glafs with a fmall camel's hair
pencil dipped in lake, ground thin with oils, which
muft be done with great exaclnefs; after this is ac-
complifhed, take a fheet of paper of the fame fize,
and place it on the glafs, ftroking over all the lines
with the hand, by which means the colours will
adhere to the paper, which muft be pierced with
pin holes pretty clofe to each other. The paper in-
tended to be ufed for the painting muft next be laid
upon a table and the pierced paper placed .upon it ;
then with fome fine pounded charcoal, tied up in a
piece of lawn, rub. over the perforated ftrokes, which
will give an exaft outline. Great care muft be
taken not to brufh this off till the whole is drawn
over with fketching chalk, which is a compofition
made of whiting and tobacco-pipe clay, rolled like
crayons; and pointed at each end.

When