Blake Purely Packaging 490 x 330 mm Corrugated Envelopes Plastic Free Peel & Seal Tamper Evident Recycled (PCE70) Brown Kraft Pack of 100

ManoMano

This quality envelope is made from rigid, corrugated cardboard for extra strength and security in transit. The envelope features a simple and secure peel and seal closure, and a handy, tamper evident rip strip opening. This pack contains 100 board envelopes measuring 490 x 330mm and is suitable for A3 documents.

Amazon

Secure Peel and Seal Closure for ease of use, added security and extra shelf life Made from rigid, corrugated cardboard providing extra strength and security during transit. Rip strip opening ensures contents arrive safe and secure. Peel & seal sealing provides instant adhesion with no need for packing tape

Zoro Tools

Made from corrugated cardboard these envelopes provide extra strength and security for transit. Security features include; increased capacity internal fold lines, rip strips and peal and seal sealing, resulting in a tamper proof postal solution.