9.5" x 12.5" Stay Flat Envelope

9.5 x 12.5 stay flat envelopes from Flextribe are sized exactly for the most common B2B shipping job: getting 8.5 x 11 documents, 8 x 10 photo prints, magazines and lookbooks to their destination without a single crease. Made from 420 GSM heavy duty cardboard, this 9.5 x 12.5 mailer refuses to bend, fold or buckle through carrier sorting machines, rough handling or weather. The white, label-ready finish takes ink, stamps and shipping labels cleanly, so there is no smudging when your team is processing dozens of mailers a day.

The 1.97 inch flap on the 9.5 x 12.5 rigid mailer folds back fully so you can load contents without fighting the envelope, and the inner dimensions of 9.46 by 12.46 inches give 8.5 x 11 paper a comfortable margin with no room to slide around in transit. The self-adhesive seal strip closes each 9.5 x 12.5 mailer in seconds without tape, scissors or extra tools. On the receiving end, a built-in tear strip opens cleanly along the back so the unboxing stays damage-free, which matters when you are mailing certificates, signed contracts or anything where presentation counts. Every pack ships with 200 free Do Not Bend stickers so your carriers know exactly how to handle these packages.

This is the right size for offices mailing legal documents and signed contracts, print shops fulfilling 8.5 x 11 certificate orders, photographers shipping 8 x 10 portrait prints, and ecommerce brands mailing lookbooks or magazines. The cardboard is fully recyclable, and bulk pack sizes are priced to bring the per mailer cost down meaningfully when you are shipping 50, 100 or more units regularly. If your packaging needs to look professional and arrive flat the first time, the 9.5 x 12.5 stay flat envelope is built for the job.

• Sized for 8.5 x 11 documents, 8 x 10 photo prints, lookbooks and magazines with comfortable margin
• Heavy duty 420 GSM cardboard keeps contents perfectly flat from pickup to doorstep
• 200 free Do Not Bend stickers included in every pack so carriers handle shipments with care
• Self-adhesive peel and seal strip closes each mailer in seconds, no tape or scissors needed
• Built-in tear strip on the back gives recipients a clean, damage-free unboxing

• Offices and law firms mailing 8.5 x 11 legal documents, contracts and signed agreements
• Print shops fulfilling 8.5 x 11 certificate orders, diplomas and document prints
• Photographers shipping 8 x 10 portrait prints, proofs and portfolio samples
• Shopify and Etsy sellers mailing art prints, posters and oversized greeting cards
• Ecommerce brands and subscription boxes sending lookbooks, magazines and catalogs