Most self-mailers are created from a single piece of durable paper or cardstock, which is folded into panels and secured with adhesive tabs or glue spots to keep it tightly closed during transit.
For the best processing, clip or spot seal the right and left edges of the self-mailer in addition to the top.
Fold-over self-mailers may have perforations around the edges for opening the item.
For the best processing, continuously seal all four edges, preferably with no gaps larger than 1 mm.
If you use a continuous glue strip, you must apply it along the entire length of the shorter panel’s top edge. The top and bottom panels must not meet in the middle.
If you’re using a perforated clip seal, test the strength of your perforation by bending it back and forth at least five times. This will ensure your mail item is strong enough to withstand machine processing.