" when the burin was moved across the grain. Tones and textures
approaching the scale of copper plate engraving could be created,
except, of course, that the lines were white and the impressions not so
brilliant. But since grays were achieved by the visual synthesis of
black ink and white paper, it mattered little whether the engraved lines
were black or white so long as the desired tones could be produced.

[Illustration: Figure 3.--Late 15th-Century White-Line Engraving "The
crowning of the Virgin," in the "dotted manner" executed on metal for
relief printing. Parts were hand colored.]

For purposes of realism, this was an enormous improvement over the old
black-line woodcut. Natural tones and textures could be imitated. The
engraver was no longer a mere mechanical craftsman cutting around
existing lines; special skill was needed to translate tones in terms of
white lines of varying thickness and spacing. The opportunity also
existed for each engraver to work his own tones in his own manner, to
develop a personal system. In short, the medium served the same purpose
as copper plate line engraving, with the added virtue that it could be
printed together with type in one impression. If it failed artistically
to measure up to line engraving or to plank woodcut, this was not the
fault of the process but of the popular reproductive ends which it
almost invariably served.

Actually, white-line engraving for relief printing dates from the 15th
century. The most conspicuous early examples are the so-called "dotted
prints" or "gravures en maniere criblee," in which the designs were
brought out by dots punched in the plates, and by occasional engraved
lines (see fig. 3). Until Koehler's[10] study made this fact plain,
19th-century critics could hardly believe that these were merely
white-line metal relief prints, inked on the surface like woodcuts. But
a number of other examples of the same period exist which were also made
directly on copper or type metal--the method, although rudimentary,
being similar in intent to 19th-century wood engraving. One of these
examples (fig. 4), in the collection of the U. S. National Museum, is
typical. This was not simply an ordinary line engraving printed in
relief rather than in the usual way; the management of the lights shows
that it was planned as a white-line engraving. The reason for this
treatment, obviously, was to permit the picture and the type to be
printed in one operation.

The