New requirements apply to commercial letters and postcards using tabs, wafer seals, and glue strips.
To learn more, view the full pdf on USPS.com.
Unenveloped letter-size mailpieces prepared for machinable or automation mailings must be sealed or glued completely along all four sides (or unsealed edges) or cured (tabbed) to prevent an open edge from jamming high-speed processing equipment. Standards for tabbing folded self-mailers, booklets, or postcards are based on basis weight of paper stock used and the location of the folded or bound edge. As an alternative to tabs or wafer seals, the open edge of the length of single-sheet self-mailers and postcards, and specific booklet designs, may be continuously glued or spot glued.