Envelope X-Ray Spray. $19.99. Yes folks, another in a regrettably long line of sleazy sweat tech.
Envelope X-RAY Spray turns opaque paper temporarily translucent, allowing the user to view the contents of an envelope without ever opening it. 30 seconds after the application, the envelope will return to its original state, leaving absolutely no markings, discoloration, or other indications of use. Each can treats several hundred square inches.
Worthy of note — the same amazing feat can be accomplished with a can of air-duster turned upside down — the pressure agent is, much like this thing, a clear liquid that renders paper transparent(ish) until it evaporates. Turning it upside down causes it to dispense less air, and more liquid. Also leaves no staining or wrinkling – generally I would expect three or four cans to be had for the price of this “product” and I’m certain the air duster is more readily at hand in most ferret dens
I refuse to believe that it leaves no trace of use.
Air duster? Bizarre! :-)