The size was a little smaller than what we needed - we really needed an 11.5in width envelope. Normally our postage machine seals envelopes with little to no problems I had to run these through multiple times before they would actually seal - and after they were "sealed" they opened very easily. It may have just been the machine but I wish they would have sealed better. I really didn't want to have to sit and lick 1 000 envelopes! :)
This is a very useful-sized envelope. I really need to find white ones however. I bought these out of desperation because a regular #10 envelope will fit comfortably into it.