INVISIBLE MARKS SPOT RANSOM MONEY (Jul, 1937)

They’re not kidding when they call the dye “new”.  Ultraviolet fluorescing dyes and paint had been developed by the late Robert Switzer and his brother Joseph in 1934 as described here

INVISIBLE MARKS SPOT RANSOM MONEY
Dipped in a new chemical solution and dried with a hot iron, ransom money is indelibly marked for identification. The preparation leaves no mark that a crook could detect, but the impregnated portion of the bill, which may be simply a strip along the edge, glows brilliantly when a bank teller holds the money under the invisible rays of an ultra-violet lamp.

3 comments
  1. Hirudinea says: June 15, 20121:53 pm

    Ultraviolet glow is a standard feature of money now, since this is from ’37 I wonder why this feature wasn’t added sooner?

  2. Toronto says: June 15, 20126:48 pm

    Different thing, Hiru. Bills these days are marked to help squelch counterfeiting, but the article is about one-time marking to prove the money is from a known source (eg a ransome, or a bank heist.)

    I have read that banks sometimes kept marked bills in the back of the till, that they’d usually leave alone but would toss in with the ‘take’ in a robbery. If you caught the robbers you had proof it was your money in their hands. If they ran and spent it, and another bank detected it and contacted police, you had a crude tracking system.

    I love the photo of the guy ironing the bills. It’s so.. Felix Unger.

  3. Hirudinea says: June 16, 201212:37 pm

    @ Toronto – I know that they used this for marking ransom money but counterfeiting goes back … well to the start of money, so you think somebody at the mint would have thought, “Hey, you know what this UV ink could be used for.” As for ironing the money his wife probably got on him for being a slob. :)

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