Fine presswork is the art of printing perfect impressions from the
surface of type or engravings in relief: that is, the subject transferred
to paper should be an impression from the surface, and the surface only,
of the types or engraved lines, of such a tone as to produce all the
effect of which the subject is capable, without either superfluity or
deficiency of colour.
The press ought to be in the best condition; otherwise it will be
impossible to get an equal impression without much trouble and loss
of time. The joints of the tympan should not have any play, or the
correctness of the register will be affected, and slurs and doubles be
caused.
The parchments on the tympans should be thin, and of a uniform thickness,
and stretched on the tympans so as not to be flaccid. On account of its
thinness, smoothness, and uniformity, silk is probably preferable.
The face of the platen ought to be a true plane, and parallel to the
press-stone, or table.
The advantage of having a good press is unavailing for the production of
fine work if the types are much worn; for it is impossible to produce
a sharp, clear impression when the type is worn and the fine lines are
rounded by much use. In consequence of this roundness of the letter, it
is necessary to use a thick blanket in the tympan to bring up the type;
thus producing a gross and irregular impression of more than the surface.