Measuring 262mm x 375mm externally CP 010.06 Rigid All Board Envelopes are made of durable E-flute corrugated cardboard that has been pre-creased for a variable capacity of up to 50mm. The pre-creasing means it’s quick and easy to customise the depth of your envelope to best match the contents for a snug, secure fit. No extra void fill is needed, making packing faster. At maximum depth internal dimensions are 250mm x 360mm x 50mm*, suitable for many books, material samples, electronics, brochures and documents that need to be keep flat and protected during the postal process. Easy to pack with an integral self-adhesive closure strip that forms a permanent seal, and easy to open with a fast access tear strip for customers, Rigid All Board Envelopes are even safety tested to avoid the risk of paper cuts during packing or opening. *Effective size decreases with increasing thickness