5 ms·

This. There are relatively few visual cues for laypeople to detect counterfeit older (and even moderately recent) US dollar bills. There are no UV sensitive are

This. There are relatively few visual cues for laypeople to detect counterfeit older (and even moderately recent) US dollar bills. There are no UV sensitive areas, the watermark line is rather faint and there's no special stuff like holographic images, transparent inserts or metal foils etc. The only way I've really seen people check medium denomination ($10s, $20s, $50s) bills is via an iodine pen test which would react to starch in regular paper but is un-reactive on real bills which are actually printed on a fabric-based material. For large denominations ($100s) many places just don't accept them...

eesmith 4y ago
Some people (James Randi in particular) spray starch on real bills to increase the false negative rate. http://archive.randi.org/site/jr/070105quality.html#7 http://archive.randi.org/site/jr/070105quality.html#7 That link also contains an account of the problems someone faced when using that technique.
- Double_a_92 4y ago
  What are other causes that make the pen fail? How does starch randomly end up on money?
  - eesmith 4y ago
    https://en.wikipedia.org/wiki/Counterfeit_banknote_detection_pen#False_positives https://en.wikipedia.org/wiki/Counterfeit_banknote_detection... > The effectiveness of the pens may be affected by external methods. Simply having a banknote pass through laundry, depending on the soaps and bleaches used, can cause a bill to fail the test when it is otherwise accepted.
Theodores 4y ago
Who benefits from this? I do not believe it is anything other than deliberate. For decades the US money has been substandard compared to what other developed countries use. By comparison US dollars are like cheapskate Monopoly money, given the colours of the notes are the same. Cheques and hand written signatures for credit card purchases have survived far too long in the US, the French had PIN in shops in the 1980's with nobody complaining about the lack of bounced cheques with forged signatures. Please fill me on the cultural differences I am missing. Why does the US have a currency that seems practically designed for forgery and smuggling?

eesmith 4y ago

Some people (James Randi in particular) spray starch on real bills to increase the false negative rate. http://archive.randi.org/site/jr/070105quality.html#7 http://archive.randi.org/site/jr/070105quality.html#7 That link also contains an account of the problems someone faced when using that technique.

Double_a_92 4y ago
What are other causes that make the pen fail? How does starch randomly end up on money?
- eesmith 4y ago
  https://en.wikipedia.org/wiki/Counterfeit_banknote_detection_pen#False_positives https://en.wikipedia.org/wiki/Counterfeit_banknote_detection... > The effectiveness of the pens may be affected by external methods. Simply having a banknote pass through laundry, depending on the soaps and bleaches used, can cause a bill to fail the test when it is otherwise accepted.

Theodores 4y ago

Who benefits from this? I do not believe it is anything other than deliberate. For decades the US money has been substandard compared to what other developed countries use. By comparison US dollars are like cheapskate Monopoly money, given the colours of the notes are the same. Cheques and hand written signatures for credit card purchases have survived far too long in the US, the French had PIN in shops in the 1980's with nobody complaining about the lack of bounced cheques with forged signatures. Please fill me on the cultural differences I am missing. Why does the US have a currency that seems practically designed for forgery and smuggling?