Our 344mm x 344mm brown all board envelopes are perfect for protecting documents, papers, card and other slim items during transit and are perfectly sized for sending 12\" records. Make packing quick and easy, and eliminate the need for packing tape with the peel and seal adhesive closure that offers a strong, secure, tamper evident closure; ensuring your documents are kept safe. Made from 400gsm high strength brown solidboard, these mailers offer a great level of protection whilst being lightweight enough to not add to postal costs. Perfect for creating professional looking packaging, our mailers offer a rustic finish that helps highlight their excellent eco-credentials. Recyclable, biodegradable and plastic free, these envelopes are made from recycled, sustainably sourced materials that make them the ideal packaging solution for eco-conscious operations.