I just pickup up a box of No. 6 3/4 EasyClose Privacy-Tint Envelopes and I have already used one so I can tell you on good authority about their features. I found that I could put a check inside and a piece of folded paper rip off the adhesive cover write an address on the front pop a stamp on the upper right corner and put it in the mailbox. These envelopes work amazingly well. By the way after I put the check inside I held it up to the light and I could not make out any writing on the check. That security feature really fantastic! I'm very happy that I still have 99 of these envelopes. They probably will last me almost 2 years. But I'll probably go back to Staples and buy another box next time I need envelopes. If you need envelopes you really can't go wrong getting these.
What's to say envelopes are envelopes. Well thats what I thought too except for a prior purchase at a different sight. Safety envelopes should have some weight to them not feel like onionskin! And you could see right through the envelopes. Happily this purchase from Staples was EXACTLY what I wanted. Couldn't be happier! Thanks Staples. :-)