The position of the final fold and intermediate fold (or spine) for letter-sized booklets varies according to the specific design of the mailpiece. Open edges can be sealed with tabs, glue lines, or glue spots. See the exhibits in sections 4-6 through 4-9 for design and sealing standards by type of design.
Note: When using tabs as seals on the leading edge of small booklets less than 5" high, mailers may place them closer to the top and bottom edges than shown in the exhibits in 4-6, 4-8, and 4-9, and in fact the tabs may overlap in some cases. Also note the exception of the simple spine wallet-style design in Exhibit 4-7, which has a maximum height of 4".
