PURPOSE: To strongly excite a receiver of a direct mail one's self to open the envelope.

CONSTITUTION: An address 1 and a picture 2 are printed on an envelope 10 by a printing part 25 according to the address information fetched from a character information file 21 based on customer information and the picture information peculiar to the customer corresponding to the address information fetched from an image information file 22. An envelope forming system comprises the steps of fetching the address information from the character information file 21 based on the customer information 23, fetching the picture information peculiar to the customer corresponding to the address information from the image information file 22 and printing the address 1 and the picture 2 on the envelope by the printing part 25.