I did not give this product the "5-Stars Rating" because I am not overly impressed with the adhesive that's used to seal these envelopes. It works very very well UNLESS you happen to "accidentally touch" the sealing adhesive several times while sealing the envelope. Then they tend to not seal very securely and often can/will "pop back open" requiring a piece of Scotch tape etc. to make a secure seal. Other than this one slight flaw these are very good envelopes!