Update, 7/18/2013: My Archbooks Architecture of the Book Encyclopedia article on Grangerizing is now available: http://drc.usask.ca/projects/archbook//grangerizing.php
Grangerizing is the expansion of a published book through the addition of illustrative images such as prints and etchings, as well as (to a lesser extent) textual material such as correspondence and playbills. Images are affixed on extra pages rebound into the codex (i.e. interleaves) or simply added on top of the existing text. This visual form of annotation is named after James Granger, an eighteenth-century collector, clergyman, and writer whose early use of the technique was rewritten as its origin; the technique was in vogue in the eighteenth and nineteenth centuries before the rise of cheap printed images and books.
Devotees of the popular hobby of Grangerizing argued that their reuse of visual material from other books was an “exquisite handicraft” that made use of texts that would otherwise have been junked (“Extending”). This reuse was another factor where Grangerizing and extra-illustration tended to differ; Grangerizers freely cannibalized other books to find the best images for their chosen text, while “extra-illustration” was a term usually applied to techniques that did not leave other books mutilated (Jackson 186). This cutting up of books caused a divide among book collectors as well as controversy with the general public; where the Grangerizers saw their work as curation and preservation of the best in image and text, others pointed to the increasing likelihood of encountering mutilated books with images (and often nearby text) snipped out.
For the book collectors whose goal was to preserve fine and historically interesting volumes as they were created, Grangerizing was a perversion of a long-celebrated activity–according to an 1892 critic, “‘breaking up a good book to illustrate a worse one” (“Extending”). The author of the 1809 treatise The Bibliomania speaks of “the mischief which this passion for collecting prints has occasioned” (Jackson 189). Bibliographic discussions from the eighteenth and nineteenth centuries are replete with colorful invective against the Grangerizers’ depredations, for which Holbrook Jackson's The Anatomy of Bibliomania is a rich and lighthearted source (especially the chapter "Grangeritis Diagnosed"). Some highlights:
“Extending the Book: The Art of Extra-Illustration”. Notice and notes for an exhibition at the Folger Shakespeare Library, Washington, D.C. Curated by Erin C. Blake and Stuart Sillars, with LuEllen DeHaven. http://www.folger.edu/template.cfm?cid=3346&CFID=2324710&CFTOKEN=60961550
Jackson, H. J. Marginalia: Readers Writing in Books. Yale University Press, 2001.
Jackson, Holbrook. "Of Grangeritis". The Anatomy of Bibliomania. 2nd Printing. Farrar, Straus, and Co., 1950. 576-582.