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.
Physical Standards (201.3.11)
Number and location of tabs or wafer seals are specified for particular types of letter-size mail. In all cases, additional tabs may be used.
Tabs, wafer seals, cellophane tape, or permanent glue (continuous or spot) must not interfere with recognition of the barcode, rate marking, postage identification, or required address information. In all cases additional tabs or seals may be used. Cellophane tape is not acceptable within the barcode clear zone. Tabs or wafer seals placed in the barcode clear zone must contain a paper face meeting the standards for background reflectance and, if the barcode is not preprinted by the mailer, the standards for water-based ink.
Adequate adhesion is required.
Basis weight: the minimum basis for paper weight standards vary, depending on the construction of the mailpiece.
Letter-Size Folded Self-Mailers (201.3.14)
A folded self-mailer is formed of panels that are created when one or more unbound sheets of paper are folded together and sealed to make a letter-size mailpiece. The number of sheets in the mailpiece and the number of times the sheets are folded determine the number of panels. Sheets that are bound by one or more staples are not considered folded self-mailers even when all other preparation recommendations are met.
Folded Self-Mailer Reference Material, including mailpiece exhibits, is updated routinely. The most recent information is located at: ribbs.usps.gov/index.cfm?page=fsm.
Letter-Size Booklet-Type Mailpiece (201.3.15)
The mailpiece must be tabbed (secured) with nonperforated 1-1/2 inch tabs, glue, or 1-1/2 inch wide tape. See DMM 201.3.15 for illustrations and design details for booklets.
Minimum basis weight 75 pounds, or greater, book grade paper stock. Double postcards must have folded edge at the top or bottom. The open edge must be secured with one tab in the middle.