Wiktionary
n. A page torn from a periodical.
WordNet
n. a sheet that can be easily torn out of a publication
Wikipedia
In advertising, a tear sheet is a page cut or torn from a publication to prove to the client that the advertisement was published. Media buying agencies are often required by clients to provide tear sheets along with a post analysis of any advertising campaign. The publishers of any periodical are legally required to provide a tear sheet upon request of any advertiser. With the emergence of online advertising tear sheets often now appear in the form of a PDF file, known as a "virtual tear sheet", or "electronic tear sheet".
In finance, a tear sheet provides a one-page summary of a company or portfolio, containing current and historic information on the company such as market cap, sector, graph of historic share price. They can also be referred to as "Fund Fact Sheets" or "Ditos".
Tear sheets are also used by writers/photographers as proof that their article/photo was published.
Usage examples of "tear sheet".
She had a tear sheet of the first ad, a comp of the second, a ream of scribbled notes and a stack of typed ones.
He tucked the tear sheet back into its envelope and stuffed it into his back pocket with the rest of the mail.
It was a magazine tear sheet that showed me in a red parka and white earmuffs.