Dye migration is one of the most common and costly print defects on polyester. The dyes in polyester become reactiveated under heat causing it to bleed into your ink... espcially with white.
You can check your garments for dye migration in your own shop. A simple test can help you know, in advance, what your garment and ink will do, avoiding bad prints and wasted material.
Why Test?
Every polyester garment bleeds but each one will bleed to a different degree. Some dyes are stable, others are not. Testing in advance helps us divide polyester garments into three tiers:
- Low risk – printable with low-bleed inks
- Medium risk – will require testing with low-cure inks or additives
- High risk – will need to use a dye-blocking underbase or a special solution
How to Test
Follow the following steps to find out how a garment will respond to being heated and find the amount of bleed to expect.
Required Tools & Materials
- Heat Press
- Donut Thermometer Kit (Optional but optimal to verify surface temperature)
- Test garment fabric (cut 4” x 4” swatch from actual production garment)
- Pellon non-woven interfacing
- Plasticizer (e.g., Thinner DT/Reducer #4) or clear gel ink
- AATCC Gray Scale for Staining (recommended for accurate grading)
Test Procedure
1. Set and Confirm Heat Press Temperature
- Set the heat press temperature to 320°F (160°C).
- Confirm actual platen surface temperature using your donut probe.
2. Arrage Materials
- Lay the 4” x 4” garment swatch face-up on the lower platen.
- Add a US quarter-sized amount of plasticizer to the fabric.
- Put a Pellon square on top of the ink area.
3. Press the Swatch
- Apply medium pressure for 30 seconds.
4. Check Results
- Inspect the Pellon for discoloration.
- Compare results to the AATCC Gray Scale for Staining to give the garment a score.
| Gray Scale Score | Assessment | Recommendation |
| 5 - 4 | Excellent | Low migration. Use low-bleed or standard whites. |
| 3 - 3.5 | Moderate | Use low-bleed inks but check production. |
| 2.5 or lower | High Risk | Use dye-blocker underbase and low-cure ink. Test before printing. |
Summary
By testing in-house you can find your dye migration risk and make better choices about:
- Ink selection
- Underbase needs
- Cure temperatire
- Dye migration of the selected garment