Aimoh's 10x13 security catalog envelopes (39100). These envelopes are made from high-quality 28lb paper, which is strong and durable, preventing them from tearing or peeling during transit. Our security pattern ensures the safety of your private information. The self-sealing QUICK-SEAL flap makes it easy to seal your envelopes quickly and securely. Each box contains 100/300 envelopes, making them ideal for both home and business use!