Which tool is used to detect counterfeit money by marking larger denomination bills?

Which tool is used to detect counterfeit money by marking larger denomination bills?

• A. Counterfeit Pen
• B. Security pen
• C. UV light
• D. Magnetic pen

Answer: (A)

This item tests a quick chemical check used to differentiate real money from fake by applying a marker that changes color based on paper composition. The counterfeit pen uses an iodine-based solution. When you apply it to a bill, the result depends on the paper type: real currency is made from cotton and linen fibers and contains little to no starch, so the mark stays yellow. Many counterfeit notes are printed on wood-pulp paper that contains starch, and the iodine reacts with that starch, turning the mark dark brown to black. That color change gives an immediate visual cue to flag suspicious notes, particularly on larger denomination bills that are more commonly targeted. UV light can reveal security features like special threads or microprinting, but it doesn’t involve marking the note with a chemical that indicates a counterfeit. A “security pen” can be another term you might encounter, but the specific tool described here is the pen that marks the bill to show the starch reaction, which is the most reliable quick check in cash handling.

This item tests a quick chemical check used to differentiate real money from fake by applying a marker that changes color based on paper composition. The counterfeit pen uses an iodine-based solution. When you apply it to a bill, the result depends on the paper type: real currency is made from cotton and linen fibers and contains little to no starch, so the mark stays yellow. Many counterfeit notes are printed on wood-pulp paper that contains starch, and the iodine reacts with that starch, turning the mark dark brown to black. That color change gives an immediate visual cue to flag suspicious notes, particularly on larger denomination bills that are more commonly targeted.

UV light can reveal security features like special threads or microprinting, but it doesn’t involve marking the note with a chemical that indicates a counterfeit. A “security pen” can be another term you might encounter, but the specific tool described here is the pen that marks the bill to show the starch reaction, which is the most reliable quick check in cash handling.