Salmon, William: Polygraphice; Or, The Art of Drawing, Engraving, Etching, Limning, Painting, Washing, Varnishing, Colouring and Dying: In Three Books ... (London, 1672)

CHAP. XL
Os Fimjhing the Work.
|, A LL the fdrmer operations Being
/\ done, wa(h the Plate with fair
water $ and put it wet upon the fire,
till the mixture be well melted, and then
wipe it very clean on both sides with a
linnen cloth, till you have cleanfed it of
all the mixture.
II. Take Charcoal of Willow, take
bff the rind of it, and putting fair wa-
ter on the Plate, rub it with the Char^
coal, as is ydu were to polish it, and it
Will take oss the Varnisti.
Where note,that the Coal rriust be free
from all knots dnd roughneis, and that
ho sond or silth sall upon the Plate.
III. Take ordinary Aqua sords, to
which add two third parts of water, and
with some linnen rags dyed therein, rub
the Plate all over, 10 will you take a-
way its discolouring, and recover its
sormer beauty.
I i IV, then