Heavy duty board back envelopes in white and manilla, made using 1000 micron backing board and a heavyweight face paper to ensure protection when posting bendable items.. Box Quantity: 125. Pallet Quantity: 14,000. Features. Self-adhesive closure. Yes. Media weight. 120 g/m². Window. No. Product colour. Beige. Material. Paper. Envelope format (ISO 269). Not applicable. Weight & dimensions. Length. 240 mm. Width. 165 mm. General. Product family. Purely. Product series. Packaging