- A4 sized, measuring 4-1/2 x 6-1/4 inches, perfect for 4x6 sized cards and photographs. - Fits Perfectly 4x6 Photo Cards, Featuring a classic square flap, this envelope is also suitable for social and invitational purposes.

Subsequently, question is, what is the standard envelope size for mailing? To be eligible for mailing at the price for letters, a piece must be: Rectangular. At least 3-1/2 inches high x 5 inches long x 0.007 inch thick. No more than 6-1/8 inches high x 11-1/2 inches long x 1/4 inch thick.

Subsequently, one may also ask, will a 4x6 photo fit in a regular envelope?

Fits neatly inside an A6, A7, or larger envelope. 4x6 - (4 1/8 x 6 1/8) - Often used for 4x6 photos or invitations.

What size is a #4 envelope?

COMMON ENVELOPE NAME STANDARD SIZE MAXIMUM ENCLOSURE SIZE 6 x 9 envelope 6 x 9 inches 5-3/4 x 8-3/4 inches 9 x 12 envelope 9 x 12 inches 8-3/4 x 11-3/4 inches 10 x 13 envelope 10 x 13 inches 9-3/4 x 12-3/4 inches