_Printing on Wood._—To print on a wood block a design to be engraved on
the same presents certain difficulties. In the first place, the
sensitizing solution must not be absorbed by the wood, but remain wholly
on its surface; then the photo film, although thick enough to produce an
image sufficiently intense to be distinctly visible in all its details,
should not scale or clip away under the graver, and not interfere in any
way with the work of the artist; the least touch of the graver must reach
the wood and make its impression. Lastly, the design should be permanent.
These difficulties will be avoided by adhering to the instructions given
in the lines following.