The envelopes do secure the information in its favor. However the envelopes slant and glue ends leave room for anyone who wants to "accidentally" open the envelope or such to open it. You have to finish sealing with scotch tape for security. It adds more time to the project. Very disappointed!
They were very easy to use. Are you have to do is peel the strip off and close it. You can't see what's in the envelope because of the security can't. I really like them.