Another Term For Zip Letters

[Brandon G.]

I'm wanting to do some research on zip letters, but I can't seem to find any information when I search for "zip letters" except for from sites who sell them as marketing pieces. I'd like to read some info on them from somewhere other than companies who sell them. Is there another term to describe them?

[Lamar Cannon]

Most other places call them "snap pack mailers". I've received a few samples of them but most are printed on 24lb paper and are flimsy. I think YellowLetters uses 28lb (I'm not 100% certain) but I do know that theirs feel and look much higher quality and are about the same price as others I've seen. I've only sampled from from 3 or 4 places.