Relief
printing is the oldest of the printed illustration processes.
The woodcut, in which a knife is
used on the plank side of a piece of wood to carve away everything
except the lines to be printed, was invented in China during the
eighth century, and reached
Europe
around 1400. With the invention of the printing press and movable
type around 1455, the relief process, though tedious, became the
primary means of printing illustrations in books, since the lines
of the image stood up in relief in the same way as did the type,
and they could be printed together on the same press. Early printers
of scientific and medical books were quick to utilize the relief
process, setting a precedent for those who followed.
The
intaglio process, which appeared
in the mid-fifteenth century, allowed the artist to produce the
image directly instead of indirectly. Despite the fact that these
illustrations could not be printed on the same press as text pages
since they required much more pressure to print, by the seventeenth
century intaglio had generally replaced the woodcut.
A
method developed toward the end of the
eighteenth
century used engraving tools on the end grain of a hard wood,
such as boxwood, to cut away the nonprinting surfaces while creating
very fine details. This technique, which again allowed text and
image to be printed together, led to an explosion of illustrated
books, magazines, and newspapers beginning in the mid-nineteenth
century. After the invention of photography,
some wood engravers were able to mimic the appearance of a photograph.
With the invention of the relief halftone
process in the 1880s, printing blocks could be made directly from
photographs, and wood engraving became obsolete for commercial
publishing.