Can you mail Postcards with rounded corners?
Postcards can be mailed with 1/8" (0.125") radius corners only. If your card has any other radius, such as 1/4" or 3/8" it can be mailed in an envelope.
See USPS regulations here
Postcards can be mailed with 1/8" (0.125") radius corners only. If your card has any other radius, such as 1/4" or 3/8" it can be mailed in an envelope.
See USPS regulations here