Smooth white All Board Envelopes, square shaped and measuring 140mm x 140mm they are manufactured from premium grade 500 micron, 350gsm, GD2 fully coated chipboard. These sleek board envelopes can be self-sealed with the easy-to-use peel and seal strip on a pre-folded flap for closing. They are the perfect way to keep paper, card and thin items protected during despatch and have easy-open strips built in, so they are simple and fast for the receiver to open again. The smooth surface can be printed on and bonds well with self-adhesive labels.