These cardboard envelopes give a snug fit design for items up to 30mm thick. They feature a special rigidly-protective design, using strong 450gsm thick recycled board with an easily stackable format for storage. Ideal for items approximately A4 in size, the fold structure and corner stiffness of these envelopes aims to reduce damage in transit. They’re also 100% recyclable and benefit from an easy peal and seal strip closure and a red tear-strip system for easy opening.