Knockpip A5/C5 Capacity Book Mailer Envelopes 180x235mm | 400gsm Rigid Corrugated Cardboard Peel & Seal Postal Mailers | Large Letter Size | Pack of 10

• Heavy-Duty 400gsm Rigid Cardboard - Made from thick 400gsm corrugated cardboard that stays rigid in transit, protecting books, documents and flat items from bends, scruffs and crushing — far sturdier than standard padded bags or thin poly mailers
• Large Letter Compatible Sizing - A5/C5 and A4/C4 sizes fit standard large letter postal formats, helping keep postage costs low; lightweight construction keeps items under weight limits without sacrificing protection during transit
• Peel & Seal - No Tape Needed - Features a secure self-adhesive strip: simply load your item, peel the liner and press to seal; a rip-strip opening makes recipient access clean and easy with no messy tape or glue required
• Expandable Capacity Gusseted Design - Unlike flat-board mailers, the gusseted capacity design accommodates items with some depth — ideal for thicker books, catalogues, magazines, DVD cases, photo albums and document wallets
• Professional Finish For Business Use - Clean manilla kraft appearance presents a far more professional impression than plastic mailing bags; suitable for e-commerce sellers, photographers, publishers and anyone wanting their post to arrive looking the part

Knockpip Capacity Book Mailer Envelopes — Rigid Protection, Professional Finish. Whether you're an e-commerce seller dispatching books, a photographer mailing prints, or a business sending catalogues and documents, Knockpip Capacity Book Mailers deliver reliable protection with a professional presentation. Constructed from heavy-duty 400gsm corrugated cardboard, these mailers keep your contents rigid and secure throughout the postal journey — shielding against bends, pressure, and transit damage that flimsy poly bags simply cannot handle. The expandable gusseted base means the envelope can accommodate items with depth, not just flat sheets. Sealing takes seconds: peel the protective liner from the self-adhesive strip and press firmly to close. Recipients benefit from a clean rip-strip opening for easy access without scissors or tearing. Supplied flat-packed for compact, space-efficient storage. Available in A5/C5 (180x235mm), A4/C4 (234x334mm) and A3/C3 (321x467mm) and pack quantities of 10, 20, 25, 50 and 100. Ideal for: Books | Magazines | Catalogues | DVDs | Artwork | Certificates | Documents | Photographs | Gift Cards | Greetings Cards