Standards for tabbing 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 mailpiece may be continuously glued or spot glued. Continuous glue or spot glue is permissible with single sheet self-mailers and cards. In all cases, additional tabs may be used. If placed in the barcode clear zone, tabs or wafer seals must contain a paper face meeting the standards for background reflectance and ink acceptance, except when a delivery point barcode appears in the address block.
Adequate adhesion is required.
Cover must have a minimum basis weight of 20 pounds. Minimum basis weight 75 pounds or greater. Double postcards not sealed on all edges must have folded edge at the top or bottom. The open edge must be secured with 1 tab in the middle. The contents of the mailpiece prepared in sleeves or other wrappers must be sufficiently secure in the sleeve or wrapper to stay in place during processing.