Desktop Publishing Supplies Brand White Square Flap A4 Envelopes are designed to accompany 4" x 6" photos or cards! The envelopes are made from a 28lb bond / 70lb text (105 gsm) white paper stock and are inkjet and laser printer compatible. These white envelopes measure 4 1/4" x 6 1/4" each, the standard A4 size, and feature a booklet style square flap.