What Color Does Counterfeit Money Turn With a Marker?
Understand the science and practical use of counterfeit money markers. Learn to verify currency reliably, recognizing both their utility and limitations for secure transactions.
Counterfeit money poses a persistent challenge in financial transactions. Counterfeit detection markers offer a readily available tool to identify fraudulent currency. These pens provide a quick and simple way to check the authenticity of banknotes. While not foolproof, understanding their function and limitations enhances their utility in safeguarding against counterfeit bills.
How Counterfeit Detection Markers Work
Counterfeit detection markers contain an iodine-based ink solution. This solution reacts specifically with starch found in most wood-based papers, like those used in printers and photocopiers. Genuine United States currency is printed on a unique blend of 75% cotton and 25% linen fibers, which contains no starch.
When the marker’s ink is applied to a genuine bill, there is no chemical reaction due to the absence of starch. Conversely, if the ink touches paper containing starch, a chemical reaction occurs, causing a noticeable color change. This difference in paper composition is the scientific principle behind the marker’s ability to distinguish between genuine and most counterfeit bills.
Interpreting Marker Results
When using a counterfeit detection marker, the resulting color indicates the banknote’s authenticity. If the mark remains clear or turns a pale yellow, the bill is likely genuine. This outcome signifies that the paper does not contain starch, consistent with authentic U.S. currency.
If the mark turns dark brown or black, the bill is likely counterfeit. This dark discoloration indicates starch in the paper, characteristic of common printing papers used by counterfeiters. To use the marker, draw a small line on an unprinted, lightly colored area, such as the border, and observe the color change within a few seconds.
Limitations of Marker Testing
Relying solely on counterfeit detection markers has inherent weaknesses. The marker primarily detects starch, so it may fail to identify sophisticated counterfeits. For example, counterfeiters might bleach genuine low-denomination bills and then reprint them with higher denominations.
Since the underlying paper is authentic and starch-free, the marker would indicate the bill as genuine, leading to a false negative. Some advanced counterfeiters use starch-free paper or apply coatings that prevent the iodine from reacting, bypassing the marker’s detection. Environmental factors, such as humidity or temperature, and the age of the marker’s solution can also affect its accuracy.
Additional Counterfeit Detection Methods
Given the limitations of detection markers, it is prudent to employ additional methods to verify currency authenticity. Genuine U.S. currency incorporates several security features designed to be difficult to replicate.
Watermarks: Faint images embedded in the paper, visible from both sides when held to the light.
Security Thread: For denominations of $5 and higher, a thread embedded vertically within the paper glows a specific color under ultraviolet (UV) light and contains microprinted text.
Color-shifting Ink: Found on denominations of $10 and higher, the numeral in the lower right corner changes color when the bill is tilted.
Microprinting: Tiny, clear words or numbers present in various locations on bills $5 and higher, requiring magnification to see clearly.
Paper Texture and Fibers: The paper has a distinctive texture due to cotton and linen, and includes tiny red and blue fibers woven into the material.
Raised Printing: Can be felt by running a fingernail across certain areas like the portrait’s vest.
Serial Numbers: Should be evenly spaced and match the color of the Treasury Seal.
What to Do with Suspected Counterfeit Currency
If you suspect you have received a counterfeit bill, specific actions should be taken to prevent further circulation and assist law enforcement. Do not attempt to re-circulate the suspected counterfeit currency, as knowingly passing fake money is illegal. Limit handling the bill to preserve any potential evidence, such as fingerprints, by placing it in an envelope or plastic bag.
It is important to note details about how the bill was received, including the date, time, location, and a description of the person who passed it. Report suspected counterfeit currency to your local police department. Local police departments, banks, and cash processors will then submit the suspected counterfeit currency to the United States Secret Service, the federal agency responsible for investigating counterfeiting.