To ensure that the post office accepts your next big direct mail marketing campaign and it gets into your recipients hands, make sure you correctly prepare your newsletters, brochures, magazines, flyers, and other marketing materials for automation rate mailings with a wafer seal or mailing tab. The postal office requires wafer seals to prevent an open edge from jamming high-speed processing equipment at the postal office. Standards for wafer seals 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 the mail piece may be continuously glued or spot glued. Continuous glue or spot glue is permissible with single-sheet self-mailers and cards.
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.
Wafer seals and mailing tabs must not interfere with recognition of the bar code, 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 bar code clear zone. Tabs or wafer seals placed in the bar code clear zone must contain a paper face meeting the standards for background reflectance and, if the bar code is not pre-printed by the mailer, the standards for water-based ink.