Rigid Kraft
Cardboard Mailers
Some shipments must arrive flat. Photos, art prints, certificates, vinyl records, calendars, documents, books. A padded mailer cushions them, but it does not stop them from bending. A rigid mailer does.
Made from stiff kraft cardboard, the rigid mailer holds its shape through sorting machines, mail bags and letterboxes. The self-seal strip closes it in one motion: peel the liner, press the flap. A perforated tear strip lets the receiver open it cleanly, without a knife anywhere near the artwork inside.
It ships as a flat envelope, so in the UK most sizes travel at Large Letter rates instead of parcel rates. In the US, USPS charges rigid mailers at parcel prices. For anyone mailing prints or documents at volume, that difference adds up fast. Postage bands by carrier, including why USPS charges a rigid mailer package prices, are in our e-commerce packaging guide.
Good for: art prints and posters (shipped flat), photographs, certificates and legal documents, vinyl records, books and magazines, calendars, embroidery and craft patterns, gift cards.
Why flat goods ship in rigid mailers
- Stiff 350-550 gsm paperboard keeps contents flat through sorting machines and mail bags.
- Self-seal strip: peel the liner, press the flap, done.
- Perforated tear strip opens cleanly, no knife near the artwork.
- Flat format: most sizes post as a Royal Mail Large Letter in the UK.
- 100% kraft paperboard: recycle with paper where collected. FSC® option available (FSC® C232146).
- Brown kraft or white, printed inside and out with your design.
Specifications
| Material | Rigid kraft cardboard (paperboard) |
|---|---|
| Composition | 100% kraft paper board, FSC® certified available (FSC® C232146) |
| Board weight | 350 to 550 gsm, matched to size and content |
| Closure | Self-seal adhesive strip |
| Opening | Perforated easy-tear strip |
| Common sizes | 15×20, 17×23, 23×30, 25×31, 24×32 (A4+), 33×46 cm, or custom |
| Colors | Brown kraft, white, custom |
| Printing | Any logo or full design |