TopicsClose
Curing · 5 of 8 · 1 min read

How to check a cure

From most to least reliable. Use more than one: the probe tells you what the dryer is doing, and the wash test tells you whether it worked.

1Wash testWash and dry the print several times and compare it to an unwashed half. Cracking, flaking, color change or a big drop in stretch means under-cure. Wilflex suggests 5 wash and dry cycles and calls this the industry requirement.
2Thermal probeRun a probe through the dryer. Avient calls it the preferred tool because it shows the actual temperature curve and how long the ink held it.
3Temperature stripsStick them to the garment under the print. They show the peak temperature reached, not how long it was held.
4IR temp gunFast but “very inaccurate” for cure. Light inks read high and dark inks read low. Use it to find hot and cold spots, not to prove cure.
5Stretch and rubQuick checks on press, but a print can pass a stretch test and still fail in the wash.

How to run a wash test

Lawson’s method: cut a test print in half, wash one half 3–5 times (hot wash, cold rinse) and machine-dry it, then compare it with the unwashed half. Davis says wash at least 3 times; Wilflex suggests 5 cycles. Do it for every new ink, shirt or dryer setting.

Undercure or just stretched too far?

ScreenPrinting.com says undercured ink cracks in a uniform, “shattered” pattern across the print, while a film stretched past its limit splits only where it was stretched. Lawson puts it bluntly: cracking ink is almost always under-cured, unless the fabric is very stretchy. Either way, the stretch test isn’t proof; wash-test.

Sources for this guide (18)
  1. Wilflex (Avient), Ink curing tips (2020, PDF)
  2. Avient, Mapping your conveyor dryer (PDF)
  3. Davis International, FAQs
  4. Davis International, Common issues
  5. ScreenPrinting.com Help, How do you cure water-based ink?
  6. Lawson Screen & Digital, Curing plastisol inks
  7. ScreenPrinting.com Help, What is cure temp?
  8. ScreenPrinting.com Help, How do you cure plastisol with a flash dryer?
  9. ScreenPrinting.com Help, Why does ink crack in a stretch test?
  10. ScreenPrinting.com, 4 curing methods
  11. International Coatings, Curing ink with a heat gun
  12. International Coatings, How do I test to make sure my inks are properly cured?
  13. Screen Printing Magazine, Figuring out flash-curing parameters
  14. Screen Printing Magazine, Curing comes clean through wash testing
  15. ScreenPrinting.com Help, What do I need to start a shop?
  16. Lancer Group, STI direct print silicone ink system (PDF)
  17. Northwest Graphic, Silextreme silicone ink
  18. PIA/SPTF, Textile plastisol curing troubleshooting (PDF)

Ranges are starting points from these sources. When a source and your ink’s tech data sheet disagree, follow the tech data sheet.