The seal on these envelopes is not covered enough by the back of the envelope so that your documents inside are stuck to the flap when the recipient tries to open it.
I use these all the time and for the most part workable. However whenever the contents are thicker I end up having to tape all around. Bottom tab is loose at the corners with stick out cuts that can catch when going through the USPS machines. Top flap doesn't have glue far enough over to ends so again need to tape down so the envelope will go through the mail system. Need to make this a consideration of function.