Large smooth white, All Board Envelopes, measuring 381mm x 508mm. Made from premium grade 500 micron, 350gsm, GD2 fully coated chipboard, these are smart-looking board envelopes you can trust to protect paper, card and thin items during despatch. A major benefit of using these board envelopes is speed of use. They contain a pre-folded flap with a peel and seal strip, which makes securing them quick and easy. For your customer, they have a peel-open strip to enable easy opening upon receipt. Because they have a coated surface, self-adhesive labels stick fast.