A watermark on a check looks like a faint, ghostly image or repeating text embedded inside the paper — not printed on top of it. You only see it when you hold the check up to a bright light, and on a genuine check the mark shows from both the front and the back. On U.S. Treasury checks the watermark spells out “U.S. Treasury.” On personal and business checks printed on commercial security paper, it usually reads “ORIGINAL DOCUMENT,” sometimes surrounded by repeating diamonds, waves, or interlocking circles.
What the Watermark Actually Looks Like
A real watermark is soft and shadowy. No sharp edges, no bold contrast, no ink you can feel with a fingernail. The image is created during paper manufacturing by pressing a pattern into the wet pulp, which leaves some areas of the sheet thinner than others. Thinner areas let more light through, and that difference in density is what you see when the check is backlit.
Under regular office lighting you probably will not notice the watermark at all. That is the point. The mark is meant to be invisible in normal handling and to appear only when someone deliberately checks for it.
On a U.S. Treasury check, the words “U.S. Treasury” are visible from both sides when held up to light. If a Treasury check has no watermark, or if the watermark is visible without backlighting, treat it as potentially counterfeit. 1U.S. Department of the Treasury. U.S. Treasury Check Security Features
On commercial check stock, the repeating “ORIGINAL DOCUMENT” pattern serves the same purpose. The geometric shapes some issuers add are there to make hand copying harder.
How to Check for It
Hold the check up to a direct, bright light. A window in daylight works. A strong desk lamp works. As the light passes through the paper, the thinner areas that form the watermark glow more brightly than the fibers around them, and the embedded text or image appears.
You can also tilt the check to roughly a 45-degree angle under a lamp. That angle catches subtle differences in surface texture that a flat photocopy will not have.
The whole check takes a few seconds. What it reveals is something a scanner or color copier cannot reproduce: a three-dimensional variation in paper density. A photocopied check looks flat and uniform when held to light. No watermark appears, because there is nothing embedded in the paper to appear.
Real Watermark vs. Fake Watermark
Not every mark that looks like a watermark is one. The difference matters when you are trying to verify a check.
A true watermark is built into the paper during manufacturing. The pattern is part of the sheet itself. It shows from both sides under backlighting, and you cannot rub it off, erase it, or wash it out without destroying the paper.
An artificial watermark is applied to the surface after the paper is made, using translucent or chemical inks. It can look similar at a glance, but it often behaves differently: it may fade or shift depending on the angle you view it from, look noticeably darker from one side than the other, or only appear when rubbed with a coin rather than when held to light.
The two-sided backlight test is what separates them. A true watermark reads the same from either side of the check. An artificial one usually does not.
When the Watermark Fails the Test
A missing watermark on paper that should have one is a strong signal the check is counterfeit. So is a watermark that only appears from one side, sits on the surface, or is already visible without light behind it.
If a check fails the watermark test, do not deposit or cash it. Once you deposit a counterfeit check, your bank will typically hold you responsible for the full amount after it bounces, even if you already spent the funds.
Instead:
- Call the bank printed on the check to verify it — but look up the phone number independently rather than using the number printed on the check itself.
- Report the check at ReportFraud.ftc.gov. Reports submitted there are shared with more than 2,800 law enforcement agencies through a secure database.2Federal Trade Commission. ReportFraud.ftc.gov
- If you already deposited it, notify your own bank right away. Early notice may limit your liability.
- Keep the check and any envelope or correspondence it came with. Investigators may need them.
Check fraud is not a small problem. In a six-month review period following a 2023 alert, FinCEN received more than 15,400 suspicious activity reports tied to mail theft-driven check fraud alone, totaling over $688 million in reported suspicious activity. 3FinCEN. FinCEN Issues In-Depth Analysis of Check Fraud Related to Mail Theft
Watermarks and Mobile Deposits
When you deposit a check through a banking app, you are sending a photograph of the paper. The watermark depends on light passing through paper, so it does not survive imaging and cannot be verified from the photo. Mobile deposit systems rely on other signals instead, such as reading the MICR line along the bottom edge, matching the written and numeric dollar amounts, and analyzing overall image quality.
Because the watermark is invisible in a digital image, mobile deposit is not a substitute for a physical inspection on any check that feels off. If the paper is unusually thin, the printing looks slightly blurry, or a personal check has no perforated edge, hold it to a light and look for the watermark before you send it through your phone.
Other Security Features to Check Alongside the Watermark
A watermark is one layer. If it passes but you still have doubts, or if you want a second confirmation, several other features are built into check paper for the same reason.
Microprinting
Very small text — small enough that it looks like a thin line to the naked eye — is printed along the signature line or borders on most checks. Under a magnifier you can read the actual letters. On U.S. Treasury checks, the endorsement line on the back reads “USAUSAUSA” in microprint. 1U.S. Department of the Treasury. U.S. Treasury Check Security Features A photocopy usually shows this line as a solid streak or a row of dots, because standard copiers and printers cannot resolve letters that small.
Void Pantograph
Many checks carry a hidden background pattern that causes the word “VOID” to appear when the check is photocopied or scanned. On the original, the pattern blends into the background and is invisible. Copiers filter out the fine detail that hides it, and “VOID” emerges in the copy. If a check handed to you already shows “VOID” across it, that check is a photocopy, not an original.
Chemical-Reactive Paper
Security check paper is treated to react to solvents like bleach, acetone, or alcohol — the chemicals used in check washing, where a fraudster tries to erase a payee name or dollar amount and write in new ones. On treated paper, the attempt leaves stains, spots, or discoloration that reveal the tampering.
Ultraviolet Features
Some checks include ink or fibers that only glow under ultraviolet light. On U.S. Treasury checks, UV printing shows four lines of “FMS” flanked by government seals, and this printing cannot be photocopied. 1U.S. Department of the Treasury. U.S. Treasury Check Security Features If a check has been chemically altered, the UV printing may be disturbed or gone entirely. Banks and check-cashing counters often keep a UV lamp at the window for this purpose.
Bleeding Ink
U.S. Treasury checks use a security ink on the Treasury seal that turns reddish when moisture is applied. 1U.S. Department of the Treasury. U.S. Treasury Check Security Features Many commercial checks use similar reactive inks on printed elements. If the ink does not react at all to a small dab of moisture, the check may be a color photocopy rather than a genuine printed document.
Taken together, these features give you several independent ways to confirm what the watermark first suggests. A check that carries a proper two-sided watermark, readable microprinting, and reactive ink is almost certainly genuine. A check that fails any one of them deserves the phone call to the issuing bank before you take it any further.