Check fraud is mostly unglamorous: a check is intercepted in the mail, the payee and amount are chemically removed, and it is rewritten. Every feature below exists to defeat a specific version of that attack.
Feature by feature
| Feature | Attack it defeats | Where it appears |
|---|---|---|
| Microprinting | Photocopying and scanning — the tiny text blurs to a solid line | Signature line, borders |
| Watermark | Reproduction on a copier or printer | Visible when held to the light |
| Chemical wash detection | Solvent removal of ink, known as check washing | Whole face; stains or reveals a message |
| Void pantograph | Photocopying | The word VOID appears in a copy |
| Toner adhesion coating | Mechanically lifting printed toner off the paper | Coating on the print surface |
| Heat-sensitive icon | Casual counterfeiting | Small icon that fades when rubbed |
| Security screen on the back | — | Lists the features, tells a teller what to check |
| Padlock icon | — | Signals a set of industry-recommended features |
The one that matters most
Chemical wash detection. Check washing is the dominant form of check fraud in the United States: the check is stolen, usually from a mailbox, treated with a solvent to remove the ink, and rewritten for a larger amount to a different payee. Stock that stains visibly when treated defeats it, and it is standard on good blank check stock.
The behavioural counterpart is just as important: use a gel pen with permanent ink when signing, avoid mailing checks from a residential mailbox with the flag up, and deposit rather than mail where you can.
Features that live in the printing, not the paper
Some protections come from how you print rather than what you print on:
- Filling the amount box completely, so no digits can be added — software does this automatically.
- Printing the written amount to the end of the line, or padding it, so nothing can be inserted.
- Not leaving the payee field short, for the same reason.
- Printing rather than handwriting, which removes the easiest target for alteration.
What security features do not do
They do not prevent someone from copying your routing and account numbers, which appear in plain sight on every check you hand over. That exposure is inherent to the instrument. The defences are account-level: positive pay for businesses, transaction alerts, and reviewing statements. See check fraud prevention when printing your own.
Choosing stock
For personal use, standard security stock with microprinting, a watermark and chemical wash detection is sufficient. For a business issuing checks to contractors and vendors, add the void pantograph and toner adhesion coating, and buy from a supplier that lists the features explicitly on the security screen. What to look for when ordering is covered in the blank check stock buying guide.