Literally: books containing illustrations published between 1837 and 1901, and executed by British artists - or artists settled in the UK.

Books containing illustrations from the French Romantic era (which, as regards book illustrations, goes roughly from 1830 to 1880). Written in French, more often than not.

Books related to engraving, engravers and the printing trade in general. It may include essays on the History of engraving or printing, technical handbooks, etc, but it excludes monographs about a particular artist, illustrated novels, encyclopedias. Books have to be illustrated.