Short answer: Swell paper is paper with a coating of tiny capsules. When you draw, print or copy in black on the paper and run it through a heater such as PIAF, the black lines and areas rise, so the drawing can be read by touch. The best results come from carbon-based black (usually a laser printer or copier), simple images and the right heat setting.
How swell paper works
- Draw or print in black. The black must contain carbon, otherwise the paper will not react.
- Run the paper through the heater. Black areas absorb more heat than the rest of the sheet.
- The capsules expand. Lines, braille and areas are raised and can be felt.
What can you use it for?
- Maps and floor plans, for example for mobility training or orientation at a school.
- Diagrams, graphs and geometry in teaching.
- Illustrations in teaching materials and tests.
- Simple signs and overviews at the workplace.
Draw, print or copy
- Laser printers and copiers usually give the sharpest result. Larger office printers and copiers often use toner with a lot of carbon, which works well.
- Inkjet printers do not always work. Many newer inkjet printers use ink without carbon. Test before printing many sheets.
- Print one sheet at a time using the manual feed and the heavy paper setting, so the heat inside the printer does not make the paper swell.
- Let toner or ink dry completely before heating.
- Do not fold or bend the paper. Creases in the coating can be seen and felt afterwards.
The right heat
Start low and increase if the image does not rise enough. The figures below are Zychem's recommendations for their machines on a scale from 0 to 10. Other machines, such as PIAF, have their own scale, but the principle is the same.
| Image | Starting setting | Note |
|---|---|---|
| Fine lines | about 7 | Thin lines need more heat. |
| Thick lines | about 4 | May rise too much at high heat. |
| Large black areas | Low | Use a pattern rather than a solid black area. |
Do not run the same sheet through the machine more than three times. Bubbles in raised areas mean the heat is too high, the ink is not dry, or the sheet has been through too many times.
Tips for the drawing
- One or two key points per sheet. Fingers cannot take in as much as eyes.
- Split the content. A complex image is easier to read as several simple sheets.
- Leave space. Lines and symbols that are too close merge.
- Add a key. Explain line types and patterns in braille.
- Test first. Ask a braille reader to try the first sheet.
A4 or A3?
A4 suits most tasks and ordinary printers. A3 gives room for maps and large diagrams. We sell both sizes in packs of 100 sheets: Harpo and Zychem swell paper, and the Harpo PIAF heater.
Questions and answers
Can we use our ordinary inkjet printer?
Maybe. It depends on whether the ink contains carbon. Print a test sheet and heat it before buying for a larger job.
Can we add to a drawing that has already been raised?
Yes, draw more on the sheet and run it through again. Keep to a maximum of three passes in total.
Do the paper and the heater have to be from the same manufacturer?
Swell paper from different manufacturers works the same way, but the heat often needs adjusting. Test when you change paper.
Can we get help getting started?
Yes. Write to info@inva.store.
Sources
- Zychem: Tactile graphics best practices and What is swell paper? (2026)
- Perkins School for the Blind: Tips for creating raised line images using a tactile graphics machine