acter of its own. These were not modest little pieces of purely
technical interest. The set of 24 sheets reproducing 17 paintings by
Venetian masters made up the most heroic single project in chiaroscuro,
and the 6 large landscapes, completed in 1744, after gouache paintings
by Marco Ricci, were the most impressive color woodcuts in the Western
world between the 16th century and the last decade of the 19th.

But Jackson's grand ambition to advance the woodcut beyond all other
graphic media had little public or private support and finally led him
to ruin. His efforts were made with insufficient means and with few
patrons. As a consequence, he rarely printed editions after the blocks
were cut and proofed. The Venetian set is well known because it was
printed in a substantial edition. A few additional subjects were also
sponsored by patrons, but most of Jackson's other chiaroscuros were
never published-- they were limited to a few proofs. Editions were
postponed, no doubt, in the hope that a patron would come along to pay
expenses in return for a formal dedication in Latin, but this did not
often happen. Most subjects exist in a few copies only; of some, single
impressions alone remain. Others have entirely disappeared.

With a large part of Jackson's work unknown, his reputation settled into
an uneasy obscurity which, it must be granted, has not prevented his
work from being collected. The chiaroscuros, especially the Venetian
prints, can be found in many leading collections in Europe and the
United States, but the full-color sheets after Ricci are excessively
rare, particularly in complete sets.

Jackson has long been considered an interesting figure. _His Essay on
the Invention of Engraving and Printing in Chiaro Oscuro_...,[3] with
its bold claims to innovation and merit, his adventurous career as an
English woodcutter in Europe, his adaptation of the color woodcut to
wallpaper printing and his pioneering efforts in this field, and
Papillon's immoderate attack on him in the important _Traite historique
et pratique de la gravure en bois_[4] will be discussed later. For the
moment we can say that the Essay was the first book by an Englishman
with color plates since the _Book of St. Albans_ of 1486, with its
heraldic shields in three or four colors, and the first book with
block-print plates in naturalistic colors.[5]

[Footnote 3: Jackson, London, 1754. Hereafter cited as Essay.
Other references bearing direct