Definition of wrapper

Advertising: see label.
Direct mail: paper cover wrapped around, or bound to the front and back cover of, a magazine, newspaper, or catalog. Wrappers may be as big as the cover and include an address label or may cover only the middle section; also called Belly Band. kraft-paper wrappers are used to protect publications from damage while in transit or, in the case of some "adult entertainment" titles, to conceal the name of the publication. Wrappers made of card stock with a perforated reply form are used to attach renewal promotions, subscriber surveys, and so forth to magazines. Wrappers are frequently used on last issue and next-to-last issue copies to let subscribers know their subscriptions are about to expire. Wrappers may also be used to mail supplementary material along with the publication as permitted by the U.S. Postal Service for polybag-carried materials.
Printing: paper jacket for a hard-cover book. Wrappers frequently include promotional copy about the book and author, including positive critical reviews, lists of other books written by that author, and/or the name of a book club that featured the book.