Beginning this month there are new rules from the USPS for Folded Self-Mailers (FSMs), which mail without envelopes.
The changes are:
Acceptable sizes for FSMs are 4-1/4” x 6” up to 6-1/8” x 10-1/2”. Previously, the largest dimension was 11-1/2”.
All FSMs must open at the top and fold at the bottom. No longer can they open either at the top or the bottom.
FSMs must be sealed closed using glue spots or non-perforated wafer seals. Now we must use translucent paper seals.