30 Oct
2001
30 Oct
'01
5:58 p.m.
At 14:40 -0800 10/30/01, Karsten M. Self wrote:
Yes, that would work nicely as the outside sheet.
Or "security" envelopes, possibly.
I just tried a can of compressed air (upside down so it sprays liquid), It is really, 1,1,1,2 Tetrafluoroehtane, not air. But anyway. It doesn't make a security envelope transparent but it does for plain old white envelopes. You can pick the stuff up at Radio Shack if you want to try it out yourself. Just be careful not to freeze your hands when the liquid comes streaming out of the nozzle.