Flash Cure

Between color passes on an automatic or manual press, the shirt slides under a flash-cure unit — an infrared heater mounted over the pallet — for anywhere from three to fifteen seconds. That's not a full cure; it's just enough heat to gel the surface of the wet plastisol so it stops being tacky, without cooking it all the way through. The next screen then prints cleanly on top instead of dragging wet ink into the new color.

Flash cure shows up most on jobs with an underbase or with layered colors — think a logo with a white base under a navy shirt, then red and gold on top. Skip the flash and the squeegee drags white into the red on the next stroke, muddying both. We've seen an otherwise clean four-color design come off press looking tie-dyed because an operator ran the flash unit too far above the shirt to hit temperature in time.

Getting the flash-cure step right is a balance of distance, dwell time, and unit wattage — too little and the ink stays wet enough to smear; too much and it over-cures that layer before the final bake, which can cause poor ink-to-ink adhesion between coats. Shops running heavy dark-garment jobs budget extra press time for flashing, which is part of why those orders often take longer per shirt than a simple one-color white-tee run.

Buyers sometimes assume flash cure is the same as final curing and that a flashed shirt is already wash-ready. It isn't — a flash only gels the surface of one layer; the shirt still needs a full pass through a conveyor dryer at proper temperature before the ink is actually cured and durable.