prestamped

Little did she know I was, by nature, so cheap that I'd sit there and pick the stamp off the prestamped envelope.

A postal official said the letter to Mr. Brokaw was sent in a prestamped first-class envelope, a type sold in postal vending machines.

But we found the stack of prestamped mailing envelopes which the fiend was using to get rid of the stolen treasures, and these were quite thick and large.

Nevertheless, she was intent upon mailing the fleas to someone, and as it turned out she mailed them to Al's Journal of Lepidoptera in one of the prestamped, self-addressed envelopes which Al provided for the posting of Amanda's occasional (more hallucinatory than scholarly) contributions to his magazine.