Fix a problem · 5 of 5 · 5 min read
Cure problems
Undercure: cracking, peeling, fadingThe print cracks when stretched or washed, peels after a few washes, rubs off, or looks faded.
- Looks like
- The print cracks when stretched or washed, peels after a few washes, rubs off, or looks faded. The whole ink layer has to reach the cure temperature on the ink’s TDS; gelled ink can feel dry and still be undercured (Lawson).
- Likely causes
- Dryer too cool or belt too fast
- An overloaded belt (Davis: test with a full belt of production shirts)
- Hot and cold spots in the dryer
- A thick or uneven deposit
- Additives, or non-curable reducers
- Fabric sizing or moisture in the garment
- Drafts and fans stealing heat
- Glitter and shimmer inks, which need more time
- A heat gun or flash used as the only cure
- Fix it now
- Correct the dryer first (PIA: slow the belt or raise the temperature), then wash-test. Our sources don’t clearly say whether re-running printed shirts saves them; if you try it, wash-test a re-run shirt before delivering any.
- Stop it next time
- Wash-test every new ink, shirt or dryer setting (see how to run a wash test). A stretch test is a quick screen, not proof. Measure the ink film with a probe or strips rather than an IR gun. Uniform “shattered” cracking points to undercure; a split only where it was stretched points to over-stretching.
- More
- Curing
Dye migration on polyesterWhite or light ink turns pink, gray or greenish on red, black, heather or camo polyester, either straight out of the dryer or over days.
- Looks like
- White or light ink turns pink, gray or greenish on red, black, heather or camo polyester, either straight out of the dryer or over days.
- Likely causes
- Curing too hot: sources put the risk at about 260–340°F (ScreenPrinting.com) or typically 295–330°F (Lawson)
- Regular (non-low-bleed) ink
- Ink driven into the fabric
- Stacking hot shirts
- Fix it now
- You usually can’t fix a printed shirt. Stop the run and adjust.
- Stop it next time
- Pick blanks that don’t bleed much, use a low-bleed or poly ink (with a gray or black blocker on bad bleeders), cure as low as the ink allows, and don’t stack hot shirts. Check your ink’s tech data sheet. Test the shirt before the job: Lawson presses a white-printed swatch and grades it on the AATCC gray scale, and PIA suggests testing a week ahead.
- More
- Inks
Scorching and over-curingYellow, tan or brown discoloring, especially on white or light shirts.
- Looks like
- Yellow, tan or brown discoloring, especially on white or light shirts. Over-cured plastisol can look brittle, glassy or bubbly (ScreenPrinting.com).
- Likely causes
- Belt too slow or dryer too hot (PIA)
- The garment not lying flat, so part of it gets too close to the heater
- A flash held too long
- Heather gray, already-flashed shirts and thin polyester heat faster; dark shirts absorb more heat
- Fix it now
- Light scorch on white cotton can sometimes be cleaned with a commercial scorch remover; Ink Kitchen describes dabbing roughly 50/50 hydrogen peroxide and water. Test on a scrap first. Heavy scorch is permanent.
- Stop it next time
- Lower the heat or speed the belt for that garment, keep shirts flat, and put good lighting at the end of the dryer so you catch it early.
- More
- Curing
Under-flash and over-flashUnder-flashed: the next screen lifts ink, colors smear, or the print stays tacky.
- Looks like
- Under-flashed: the next screen lifts ink, colors smear, or the print stays tacky. Over-flashed: top colors don’t stick to the underbase and peel apart after a few washes; also shrinking, shiny or scorched spots.
- Likely causes
- Flash time or height wrong for this platen and shirt
- A cold platen early in the run, then a hot one later
- Printing the next color onto a still-hot print
- Some fabrics shrinking under heat, which ruins registration
- Fix it now
- Flash at the lowest heat that gets the ink dry to the touch. Source examples range from about 180–250°F and 2–5 seconds, and over-flashing risks poor adhesion; your ink’s TDS decides. Time it with a stopwatch, warm the platens with test prints, and let the print cool briefly before the next screen.
- Stop it next time
- Write down flash time and height for each garment type.
- More
- Curing
Halo, oily ring, or shirts sticking togetherAn oily shadow around the print, or prints sticking to each other in the stack.
- Looks like
- An oily shadow around the print, or prints sticking to each other in the stack.
- Likely causes
- Ink not cured soon enough after printing
- Undercured ink
- Too much viscosity reducer
- Shirts stacked before they cooled
- Fix it now
- Cure right away after printing, fix the dryer and wash-test, and stay within the maker’s reducer limits.
- Stop it next time
- Put a fan at the end of the dryer, lengthen the take-off area, or stack hot shirts in alternating piles (PIA). Davis also says don’t stack hot shirts.
- More
- Curing
Sources: PIA/SPTF · Davis International
Sources for this guide (50)
- ScreenPrinting.com Help, Pinholes and fisheyes
- Chromaline, Causes of pinholes during screen making
- Chromaline, Underexposed screen tech tip (PDF)
- Avery Dennison, IB 8.34 silkscreen troubleshooting guide (PDF)
- ScreenPrinting.com Help, Over- vs. under-exposure
- ScreenPrinting.com Help, How do I figure out exposure times?
- ScreenPrinting.com Help, Why can’t I burn my screens correctly?
- ScreenPrintingNow, Using the 21-step wedge
- Lawson Screen & Digital, Direct emulsion troubleshooting checklist
- Avient, Print technique guide, 2023 (PDF)
- Chromaline, 10 common reasons for stencil breakdown on press
- ScreenPrinting.com, Printing with plastisol vs. water-based ink
- ScreenPrinting.com, Get rid of ghost images
- ScreenPrinting.com Help, How do you reclaim screens?
- Screen Printing Magazine, Preventing and removing haze
- International Coatings, Preventing moiré patterns
- Screen Printing Magazine, Ten tips to help avoid halftone moiré
- Solutions for Screen Printers, Halftone angles demystified
- Impressions, Troubleshooting screen printing (2018)
- Screen Printing Magazine, Catching the on-press culprit
- ScreenPrinting.com Help, Why is my print fuzzy?
- Ink Kitchen, Why out of register? Let me count the ways
- ScreenPrinting.com Help, What’s considered good mesh tension?
- ScreenPrinting.com, Registering water-based and plastisol prints
- Davis International, Common issues
- PrintWiki, Mesh marks
- Lawson Screen & Digital, Eliminating fibrillation
- Texsource, What is fibrillation?
- Fujifilm, Fibrillation in plastisols (PDF)
- ScreenPrinting.com Help, How do I pick the right mesh count?
- ScreenPrinting.com, High contrast with discharge inks
- Signs101 forum, Just started screen printing again
- ScreenPrinting.com Help, Water-based vs. plastisol
- Lawson Screen & Digital, Plastisol ink FAQ
- Lawson Screen & Digital, Reducing plastisol ink build-up
- Screen Printing Magazine, Anti-build-up additive
- PIA/SPTF, Textile plastisol curing troubleshooting (PDF)
- Lawson Screen & Digital, Curing plastisol inks
- ScreenPrinting.com Help, Why does ink crack in a stretch test?
- ScreenPrinting.com Help, Why does ink look faded after washing?
- Screen Printing Magazine, Curing comes clean through wash testing
- International Coatings, How do I test to make sure my inks are properly cured?
- ScreenPrinting.com, What is dye migration?
- ScreenPrinting.com, Decoding poly white and dye blocker inks
- Lawson Screen & Digital, Testing polyester for dye migration
- Lawson Screen & Digital, Low-cure screen printing ink
- Ink Kitchen, Scorching heat, scorching shirts
- ScreenPrinting.com Help, Can you over-cure plastisol ink?
- Screen Printing Magazine, Figuring out flash-curing parameters
- Wilflex (Avient), Ink curing tips (2020, PDF)
Where sources disagree, the page says so.