I am assuming you are in the US.

For the 5X7 you only need ONE .42 stamp.

The larger ones need at least .83, but 1.00 to be safe.

Hope this helps.

BossC

Ok... I have been collecting autographs for years now. I use both the 8x11 and I believe the other size envelopes I use are about 5x7ish. I feel like I'm using more postage than what I should use. I see that when some celebs send stuff back to me... it is exactly $1 postage for a bigger envelope. I am using 3 stamps (42 cents ea.) per big envelope and 2 stamps (42 cents each) for the 5x7 ones. Is this correct or could I use a different combination to save money? I feel like I'm going through so many so fast! Anywho... I hope someone reads this and can help me. Thanks so much!!