letter mailer

A #10 business (letter) envelope is about 4.125 × 9.5 inches (often shown as 4‑1/8 × 9‑1/2 or 4.12 in. × 9.5 in.). It’s used for standard letters and checks and is commonly sold in bulk counts such as 100–125.

Listings describe mailing boxes as stackable yet lightweight, easy to assemble, ready to address with printed sender/receiver labels, recyclable, and suitable for mailing, moving, shipping, and storage.

Some listings explicitly state envelopes are printer-compatible and run smoothly through printers. Several note they’re suitable for everyday mailings, and a few specifically call out compatibility with laser and inkjet printers.

Most mailers and envelopes are paper-based: mailing boxes are cardboard and envelopes are paper. Common finishes shown include manila/beige, white, assorted colored paper, and a smooth copper metallic option.

Security features include printed security linings that hide contents, press-and-seal/self-seal closures for added privacy, and clasp or gummed-flap closures to keep contents secure.

Listings show white and manila/beige, brown business envelopes, bright assorted colors (pink, purple, blue, green, yellow, orange), and a smooth copper metallic finish.