In short
- Press at 140–150 °C, 10–12 s, light pressure
- Use a low-temperature powder and a film rated for polyester
- Increase white density to 100 % and add a second press with parchment
Lower the heat
Every 10 °C below 160 halves the migration. 140–150 °C for 10–12 s bonds a low-melt powder perfectly and keeps most dyes asleep. Do not compensate with more time; time is exposure.
Powder and film
- Low-temperature TPU powder (melts ≈ 100–110 °C) lets you press cooler.
- Some films are sold as “anti-migration” — they add a thin barrier layer. Worth it for red, black and neon polyester.
- Cure the powder fully in the oven so you are only re-melting it in the press, not curing it.
The white layer is your blocker
A dense white underbase is what stops dye reaching the colour layer. On polyester set white density to 100 % even on light shirts, keep highlight white at 10 % and never use “less white under dark colours”.
Scorch marks and shine
- The rectangle around the design is heat-pressed polyester: the fibres flattened and went glossy. Lower the temperature, use light pressure and a Teflon sheet, and press with a piece of parchment larger than the platen.
- For sportswear with a textured weave, a pressing pillow under the garment keeps pressure even so no edge gets a shiny frame.
