Does a glossy finish cause problems with USPS mail processing?

A heavy gloss coating on the address side can interfere with the barcode and address scanning that USPS automated sorting equipment relies on. The fix is simple: keep the mailing side readable and save the shine for the design side.

• Address side: use a matte or uncoated finish so scanners and inkjet address printing read cleanly.
• Design side: gloss, UV, or any high-shine finish is fine here and helps the piece stand out.
• Why it matters: a piece that fails automated sorting can be kicked to manual handling, which risks delays.

If you want gloss on both sides, ask about an uncoated address block or a mail-safe coating before committing the run.