Check the color-shifting ink on the lower-right “100”
Look for the blue 3D security ribbon woven into the bill
Hold the bill to light and verify the watermark of Benjamin Franklin
Check for the security thread that glows pink under UV light
Feel the raised printing on the portrait, numbers, and words
Look for microprinting around the portrait and security features
Verify the bell in the inkwell changes from copper to green
Compare the bill’s size, paper texture, and printing quality to a known genuine bill
Check for crisp, sharp lines and even borders
Use a counterfeit detection pen only as a rough first check
Examine the serial numbers for consistent font, spacing, and alignment
Check that both serial numbers match exactly
Tilt the bill to see the 100 in the lower-right corner change color
Inspect the paper for embedded red and blue security fibers
Verify the bill’s overall detail and lack of smudging or blurry printing