A SPRAY that makes unopened envelopes transparent—so the letters inside
are as easy to read as postcards—has been developed by a company in the
US. And the spray leaves no trace, says its inventor, Mistral Security of
Bethesda, Maryland.
“With a business card in a brown envelope,” says company spokesman Bob
Schlagel, “you can read the card, the e-mail address, the telephone number,
everything.”
Schlagel says that the spray, called “See-Through” was developed to let
police forces inspect potentially dangerous packages, like a letter bomb.
Described as a “non-conductive, non-toxic, environmentally safe liquid”, the
spray has been tested…
