You could make the invites any size you want. The A2 envelope, 5 3/4 x 4 1/2 in is called invitation size. You could buy your envelopes in Staples or other office supply store. Incidentally, the card that fits in these envelopes is half of an 8 1/2 x 11 in paper or cardstock folded in half. HTH! Cindy