So Many Square Envelope Sizes!Something modern and different, LCI Paper supplies square invitation envelopes in common and not-so-common sizes, dozens of colors and finishes, and in multiple flap styles. Square envelopes are popular for unique wedding and Bar/Bat Mitzvah invitations, corporate mailings, fun greeting cards and more.
Square Envelope Postage
It's true - square envelopes do cost more to mail. Due to the non-machinable size and shape of square envelopes, the USPS charges a surcharge for square envelopes in addition to the current stamp price. Also note that anything over one ounce requires additional postage as well. To determine accurate postage for your square mailing envelopes, we recommend bringing one finished ensemble to the post office.
You might also like: Square blank cards