The Postal Service has identified the ten most common mistakes they encounter with mailpiece design — and has published a handy document on how to improve your mail.
1. Not meeting minimum mailing dimensions.
2. Dark/black background color on mailpieces.
3. Screening and imaging.
4. Return address placements on letters and flats.
5. Text or graphics in the Barcode Clear Zone.
6. Postcard Design.
7. Insert Shift.
8. Folded Self-Mailer Construction
9. Address Placement on Flats
10. Requesting Uniquely Assigned BRM ZIP+4 Code