olor, oil, or pastel. The
number of printings to be employed should be predetermined and a color
scale adopted. The lithographer must carefully analyze the original
painting, making his calculations as to the best way of obtaining the
desired color effects by a judicious selection and use of his colors,
and the superimposing of one printing over the other, so as to obtain
true color values. It must be remembered that, while the average
painter has an unlimited variety of pigments at his disposal, the
lithographer is in this respect very much at a disadvantage, not
usually having more than from six to fourteen colors with which to
produce a facsimile of the original.

The first step is the making of the so-called key-plate. A piece of
gelatine is laid on the original, which is, let us say by way of
illustration, a water-color to be reproduced in ten printings, and a
careful tracing of the original is made by scratching, with an
engraving needle, the outline of each wash or touch of color composing
the picture. This being completed, the lithographic ink (tusche) or
transfer ink is carefully rubbed into the tracing, which is laid face
down on a polished lithographic stone, slightly moistened, and passed
through a hand press; thereby transferring the ink from the engraved
lines to the polished surface of the stone. The design on the stone is
then rolled in with black printing ink and etched, thus enabling the
lithographer to take the necessary ten impressions of the key-plate.
These, in their turn, are again transferred to as many lithographic
stones. This is accomplished by dusting the impressions with a red
powder, which adheres only to the design printed on the sheet. The
powdered outline design is then transferred to the surface of the
stone by passing both through a hand press. The key has been
previously provided with register marks (a short horizontal line
intersected by a vertical one) at top, bottom, and both sides. These
are of the utmost importance to the prover, and finally to the
transferrer, who prepares the work for the press, as without them it
would be impossible to register one color over the other in its proper
place. At any stage of the process, the register marks of all ten
colors, which have been made in succession on a single sheet of paper,
should coincide precisely and appear as a single mark in the form of a
small cross.

The lithographer now has before him the ten stones, each stamped with
the