These envelopes are fairly basic but they don't need to be anything fancy. They self seal and you can't see through them. That's all I really need in a security envelope.
There is an easy peel-off strip; however because the glue is weak the envelop doesn't stay closed. I decided I wouldn't risk contents not staying in the envelop and threw the box away and went back to the "lick them" kind.
Yes these are #10 envelopes. They do the job. The idea that I'm asked to review these envelopes is a bit silly. Although I could say they are very romantic.