These envelopes are technically the same size as the last deposit envelopes I used (which were fine from a security standpoint) but their interior dimensions are just a bit larger and allow for business-sized checks to be inserted horizontally rather than vertically. I also like the clear envelopes which means we no longer wind up accidently cutting the larger checks, which happened with the other envelopes (which were opaque.) These work well to secure forms and information that is confidential: the receiver can be sure no one else has seen the info. Of course for that purpose I generally fold the papers for confidentiality and for ease of opening - a full sized sheet fits but I haven't sealed an envelope as I think opening it without damage to the contents could be a problem.