The adhesive did not last long. After awhile the older envelopes would not stick and hold after pulling off the protective strip. I had to reseal using adhesive tape. I bought a new box of them because that's the only brand Staples had for self-sealing envelopes that size. We'll see whether the manufacturer has improved the longevity of the adhesive or not. If not the remainder of this box will be going back just like the previous one did.