Please note: most square envelopes require additional postage. Square envelopes are perfect for announcements, special events, corporate dinners, weddings, greeting cards, holiday cards, invitations, direct mail or general use. With a sleek square flap, square envelopes are designed to compliment your stylish invitations, tasteful thank you cards or meaningful notes. Take notice of the center seam if printing on the back. These envelopes are manufactured by Envelopes.com and are sealable with Peel & Press?.