Screen Printing on Polyester: Challenges, Solutions, and Best Practices

Screen Printing on Polyester: Challenges and Solutions

Polyester is everywhere — performance tees, sports jerseys, corporate polos, and moisture-wicking athletic wear. But screen printing on polyester is not the same as printing on cotton. The fabric's synthetic nature creates unique challenges that can ruin a print job if not handled correctly.

At French Press Custom, we print on polyester daily for teams, corporate clients, and athletic brands. Here are the challenges you need to know about and how we solve them.

The Main Challenge: Dye Migration (Bleeding)

What Is Dye Migration?

Dye migration (also called dye sublimation or bleeding) occurs when the dye used to color the polyester fabric reactivates under heat and migrates into the printed ink. The result: colored halos, blotchy prints, and the garment's dye bleeding through your design.

Why It Happens

Polyester is dyed using disperse dyes that bond to the fabric at high temperatures. When you apply heat during the screen printing curing process (320+ degrees F), those same dyes can become gaseous again and migrate into the wet or curing ink — especially into white and light-colored inks.

The Classic Nightmare Scenario

You print a white logo on a red polyester polo. It looks perfect off the press. You cure it at 320 degrees F. Two hours later, the white ink has turned pink. The red polyester dye migrated into the white plastisol.

This is the number one reason inexperienced shops ruin polyester orders.

Solutions for Dye Migration

1. Low-Bleed Plastisol Ink

Specialty plastisol formulations are designed to cure at lower temperatures (270-290 degrees F instead of 320 degrees F). Lower cure temp means less dye activation and less migration.

How we use it: French Press Custom stocks low-bleed white and light-colored inks specifically for polyester jobs. These inks contain blockers that resist dye penetration.

2. Low-Cure Temperature

Curing polyester prints at the lowest effective temperature minimizes dye migration risk:

• Standard plastisol: 320 degrees F
• Low-bleed on polyester: 270-290 degrees F
• Must still fully cure — use temperature strips to verify

3. Cooling the Print Immediately

After curing, rapidly cooling the garment prevents continued dye migration:

• Cold fans at the end of the conveyor dryer
• Cool air blowers on the exit
• Do not stack warm garments — heat continues the migration process

4. Gray or Dark Underbases

On dark polyester, using a gray underbase instead of bright white reduces the contrast that makes migration visible. The gray base absorbs some migrating dye without obvious color shift.

5. Water-Based or DTF Alternative

For particularly problematic polyester fabrics (bright reds, royal blues, kelly greens), consider:

• DTF transfers — applied at lower temperatures with better dye migration resistance
• Sublimation printing — on white polyester, this is the gold standard (no migration because the dye becomes part of the fabric)

Other Polyester Printing Challenges

Adhesion Issues

Polyester does not absorb ink the way cotton does. Plastisol sits on top of the smooth synthetic fibers and can struggle to bond properly.

Solutions:

• Use polyester-specific additives in your plastisol ink
• Ensure proper cure temperature (under-cured ink has poor adhesion)
• Apply appropriate ink deposit (too thin = poor coverage, too thick = peeling risk)
• Consider using a bonding agent or primer coat

Static and Lint

Polyester generates static electricity, attracting dust and lint to the fabric surface. This can cause print defects — tiny specks, pinholes, or contamination in the ink.

Solutions:

• Anti-static spray before printing
• Lint-free environment in the print area
• Tack cloth wipe before loading garments
• Anti-static bars on the press

Scorching

Polyester has a lower heat tolerance than cotton. Excessive temperature causes:

• Fabric sheen (glossy appearance in heated areas)
• Texture change (the fabric feels different)
• Melting in extreme cases

Solutions:

• Flash cure at lower temperatures and shorter durations
• Use flash units with focused heat, not broad radiant panels
• Monitor fabric temperature, not just ink temperature

Moisture-Wicking Coatings

Many performance polyester garments have moisture-wicking treatments or coatings on the fabric surface. These can create a barrier between the ink and the fabric.

Solutions:

• Pre-test print adhesion on the specific garment
• Use inks formulated for treated fabrics
• Consider higher ink deposits for better coverage
• DTF is often more reliable on treated polyester

Best Practices for Polyester Screen Printing

Pre-Production

1. Test print on the actual garment before running the full order
2. Identify the garment's dye content — 100% polyester is most susceptible to migration
3. Stock low-bleed inks in all colors needed
4. Check the garment color — reds, blues, and greens migrate most aggressively

During Production

1. Use low-bleed or low-cure inks for all light colors on dark polyester
2. Cure at the lowest effective temperature (verify with temp strips)
3. Flash at lower temps — 250 degrees F for shorter durations
4. Cool garments immediately after curing
5. Do not stack warm garments

Quality Control

1. Print and cure 5-10 test pieces before running the full order
2. Wait 24 hours before approving — migration can continue after curing
3. Inspect for dye bleed, adhesion, scorching, and texture changes
4. Wash-test one garment to verify durability

When to Choose an Alternative Method

| Scenario | Recommended Method | |----------|-------------------| | Full-color design on white polyester | Sublimation (best quality) | | Simple logo on dark polyester | Low-bleed screen print or DTF | | Photographic image on polyester | DTF or sublimation | | Small order (under 24) on polyester | DTF (no setup cost) | | Large order on polyester | Screen print with low-bleed ink | | Problematic bright-colored polyester | DTF (safest option) |

The French Press Custom Approach

We have refined our polyester printing process over 15+ years of production. Our approach:

1. Garment assessment — we evaluate the specific fabric before printing
2. Ink selection — low-bleed formulations for all polyester work
3. Temperature control — calibrated curing with temp verification
4. Immediate cooling — forced air cooling at dryer exit
5. 24-hour hold — we hold polyester jobs for 24 hours after production to check for delayed migration before shipping

This process means virtually zero failed polyester jobs leaving our facility.

Need to print on polyester? Contact French Press Custom at (562) 758-5110 for expert handling of your performance fabric printing needs.