Now that you've made a card, it's time to send it in one of Stampin' Up!'s envelopes. With an exclusive flap design, these envelopes will give the final touch of class, especially if you stamp on it! Mini Square envelopes measure 3 1/8" x 3 1/8". Package includes 40 envelopes. The U.S. Postal Service will not deliver Mini Square envelopes.