These are the keys to addressing an envelope, so that it can be sorted by an optical character reader (OCR). This is important because it allows the U.S. Post Office to sort the mail faster and get the letter to its destination quicker.
- Dimensions of a letter size mailpiece:
| Dimensions (inches) | Minimum | Maximum |
| Height | 3 1/2" | 6 1/8" |
| Length | 5" | 10 1/2" |
| Thickness | .007" | 3/16" |
- Address Locations
- Lines of Address
- Please make sure that the three lower lines of the address has the name of recipient, the delivery address and the city, state and zip on the last line.
- Please use the Post Office approved abbreviations for the states because the machine can recognize them instantly.
- Non-Address Information
- Please keep all non-address information out of the address location that was explained above
- Bar Code Clear Area: The optical Character Reader (OCR) will place a bar code on the piece after it reads the destination of the letter. The space that the bar code will be placed needs to be clear
- 5/8" from the bottom of the piece
- 4 1/2" from the right of the piece
- Window Envelopes - Make sure that all of the address is visible through the window
- Address Characters
- The OCR can read most typewritten and other machine printed addresses
- It cannot read handwriting and print styles such as script, italic, artistic and other highly stylized characters
- Print Quality and Color
- The print needs to be clear, sharp print
- The OCR likes black ink on a white background best
- The OCR needs to have a contrast between the ink and the paper. Keep the ink as dark as possible and the background as light as possible.