USPS Automation Letter Rate
Flap Glue Seal – SPECIFICATIONS
Refer to USPS Case Number 91004
Why glue seal?
Hot melt glue is typically the fastest and most cost efficient way for a lettershop to seal a machine inserted EnvyPak envelope flap. This process is fully automatable in many lettershops. Peel and stick tape is typically the preferred seal method for hand inserting.
USPS tested and approved the two specific glue seal methods shown below. Any other seal method or glue pattern will require USPS approvals. Wafer seals are not an option.
Glue must come within .25” of the leading edge, trailing edge and bottom edge of the sealed flap.