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There are many ways to check a dollar bill's authenticity. Here are some ways to see if your dollar bills are authentic or counterfeit.
 
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Step 1: Hold bill to light

This will work on $10 bills and $20 bills. I don't know if this applies to higher denominations like $50 bills and $100 bills. Please reply if you do know. This will not work on $1 bills, $2 bills, and $5 bills. Hold the dollar bill up to the light and if you see the President's face on the right side of the bill, it's authentic. If you don't see the President's face it's counterfeit.

Step 2: The ink test

This will work on all denominations. This is commonly used to test lower denominations such as $1 bills, $2 bills, and $5 bills. Take a pen and make a streak on the dollar bill. If the ink shows the same color on the dollar bill, it's authentic. If it changes color it's counterfeit.
Lunera2 years ago
Sorry, but no. Your first one with the watermark is correct, however, it is not a highlighter that you want to use.

The pen used is a counterfeit detector pen, the ink in which, is actually iodine, giving the yellowish color you normally see.


Why iodine, and why does it work? Iodine can be used as a chemical detector for the presence of starch, like what you would find in the paper made from wood, which is why it turns dark on most papers.
But why doesn't it change on money? Surely it's paper as well right? Yes, but it's made from cotton, lined, and a small percentage of 'rag' giving the blue and red specks you can see if you look really close. That paper has no starch.
BLUEBLOBS2 (author)  Lunera2 years ago
Thanks for your help Lunera and for the education.
blueblobbs2 years ago
Did you know that there are two more test, but I'll leave you to figure them out.
-blueblobbs
You have a steady hand to fold a bill for a close up pic and let me
Clearly see Hamilton's image :-)

A
Pro

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