rwise have had but one state, thus
depriving one modern print collector of the privilege of discovering
in his proof three hairs more or less in a donkey's tail than his
rival finds in another proof, which makes the former's more valuable
by several hundred pounds.

One form of press is used for all manner of intaglio plate printing.
It consists of a framework supporting two heavy iron rollers, between
which moves a flat iron travelling plank, or bed, and on this bed the
plate to be printed is laid. The pressure of the rollers is regulated
by screws at each end of the top roller, which is covered with two or
three pieces of thick felt. This top roller is revolved by handles and
the bed moves along with it under the pressure of the roller. At one
side of the press stands a rectangular box, or "stove," made of iron,
or having an iron top. The top is heated by gas and on it the printer
puts his plate while inking and wiping it. The heat thins the ink as
it is applied, allowing it to be worked freely and to be "lifted"
easily by the paper.

The ink is made of fine bone dust, vegetable or other form of carbon,
which has been carefully cleansed from foreign matter and ground to
the necessary fineness in combination with burned linseed oil. Its
strength and consistency should be varied according to the plate which
is in hand, and the color also may be varied to suit the character of
the plate by the addition of pigments.

The paper used in plate printing may be one of several kinds, but the
usual variety is a fine white paper free from spots and imperfections
which might mar the appearance of the finished print. This paper is
made either by hand or machinery of selected bleached cotton rags, and
has a soft, spongy surface which yields readily under the pressure of
the plate. Before it can be used the paper is moistened and allowed to
stand for from one to twelve hours, or even longer, until it becomes
evenly and thoroughly dampened,--but not wet,--so that it will more
readily force itself into the lines of the plate and take therefrom
and hold the ink.

Before printing a photogravure, mezzotint, or other engraved plate the
printer must first carefully examine it to see that it has no
scratches, and that no dried ink remains in the lines from the last
printing, and, in fact, that there are none of the many possible
impedimenta which might prevent the production of a perfect print. The
plate being in proper condition, it is