Permanent ink for documents and signatures
TL;DR
For important documents, use ink that resists water, light, and tampering. Pigment-based gel inks and pens marked as meeting a documentary-use standard, such as ISO 12757-2 for ballpoints, are designed for this. Avoid erasable pens and dye-based rollerballs for anything that must last.
A shopping list can fade. A signature on a contract, a will, or a cheque should not. Ink permanence is about how well writing survives water, light, time, and deliberate attempts to remove it.
What makes ink permanent?
Several properties matter:
- Water resistance: whether writing runs or disappears when wet.
- Light-fastness: whether it fades in light over time.
- Chemical resistance: whether common solvents can lift it, which matters for fraud.
- Paper bond: whether the colour soaks into the fibres or only sits on top.
Pigment inks use solid particles that become trapped in the paper's fibres and generally resist water and fading better. Dye inks are dissolved colourants; they are often vivid but can fade or run.
What do "document" markings mean?
International standards define test methods for writing instruments intended for documents. Pens tested to them are often marked on the barrel or packaging.
| Marking | What it covers |
|---|---|
| ISO 12757-2 ("DOC") | Ballpoint pens and refills for documentary use |
| ISO 14145-2 | Rollerball pens and refills for documentary use |
| ISO 11798 | Permanence and durability of writing, printing, and copying on paper |
| ISO 27668-2 | Gel ink ballpoint pens and refills for documentary use |
If a pen carries one of these markings, the manufacturer is claiming it meets that standard's tests. Check the packaging rather than assuming.
Cheques and fraud
"Check washing" is a fraud technique where criminals use solvents to remove ink from a cheque and rewrite the payee or amount. Fraud-prevention guidance frequently recommends writing cheques with an indelible, pigment-based ink, because pigment particles bond into the paper and are harder to lift than dye.
Inks to avoid for anything important
- Erasable pens: their ink is designed to disappear with friction heat and can also disappear in heat or reappear in cold.
- Dye-based rollerballs and fountain pen inks not described as permanent or archival.
- Pencil for signatures, which can be erased.
- Very old or partly dried pens that skip, leaving gaps that are easy to alter.
Practical checklist
- Use black or dark blue pigment ink, or a pen with a documentary marking.
- Write firmly and continuously, without gaps that can be filled in.
- Let the ink dry before folding or stacking.
- Store documents away from light, heat, and damp.
Limitations
Ballgel has not tested any pen against these standards. Requirements for legal documents vary by country and institution; when in doubt, ask the bank, registry, or office receiving the document what they accept. For everyday choices see Ballpoint vs gel vs rollerball ink.