Since the beginning
of the Renaissance, the art of intaglio print making has been counted
among the great achievements of western art. Alongside the oil painting,
sculpture, fresco and architecture it has been the vehicle by which
the peoples of the occidental world have expressed their ideas, aspirations
and hopes and saved them for posterity.
The copper plate etching is a form of intaglio printmaking wherein
the grooves in the plate are not produced by carving them out with
a burin as is the case with engravings. The grooves in which the printing
inks rest are produced by exposing the copper to acid which eats into
the plate. Prints made from such plates have been extant since the
second half of the 15th century.
The plate is coated with a thin asphalt layer, which protects the
copper from the acid. The artist then draws, with a needle, the picture
into the the asphalt thereby scratching that protective layer away.
Thus revealed, the copper shines through the black asphalt, looking
much like a negative of the picture that will eventually be printed.
The copper plate is laid into an acid bath and the drawing is etched
into the copper.
Once etched and cleansed of the asphalt layer the plate is then coated
with a layer of printers ink. The excess ink is then wiped off, leaving
ink only in the etched grooves. A piece of moist paper is then laid
upon the plate and they are both rolled through the press.
Because of the pressure applied to the copper plate and the moistness
of the paper the paper itself is pushed into the grooves of the plate
thereby taking on the printers ink. The print is then taken off the
plate and cleaned. This process is repeated for every print and has,
like the method of making the plate, not changed since over 500 years.
Ruth Leaf, "Etching, Engraving and other Intaglio Printmaking Techniqes",
Dover Publication,Inc. N.Y.,1984, ISBN 0-486-24721-X.