If you still enjoy sending messages the old-fashioned way, you'll love the A2 envelope (4-3/8" x 5-3/4") – the perfect-sized envelope for letter-writers. Designed to accommodate a quarter-folded sheet of paper, the A2 envelope is just the right dimension for homemade greeting or holiday cards, too – with many colors to choose from, there's a shade for every card design you can imagine! The A2 envelope is a social and invitation-type envelope; it is also a popular size typically used for RSVP and announcements. Featuring a smart-looking square flap, the A1 envelope fits inside all "A" envelope sizes (except for the"A1" style).