If your DTG prints don’t look bright or start fading after a few washes, the problem might be the pretreatment. Pretreatment is a must-do step before DTG (Direct-to-Garment) printing, especially for dark T-shirts. It helps the ink stay on the surface, keeps colors sharp, and makes prints last longer.
In this guide, we’ll walk you through everything you need to know about DTG pretreatment—even if you’re new to garment printing.
🧪 Why Pretreatment Is Important in DTG Printing
Pretreatment prepares the fabric before the ink goes on. Here’s why it’s important:
- Makes Colors Pop – Pretreatment stops ink from soaking into the shirt. This keeps colors bright and bold.
- Keeps Edges Sharp – It helps designs stay crisp and clean.
- Prevents Fading – Pretreated shirts last longer after washing.
- Helps White Ink Stick–On dark shirts, white ink won’t print well without pretreatment.
If you skip this step, your prints may crack, blur, or wash out quickly.
🔬 What Does Pretreatment Do?
Pretreatment is a special liquid sprayed onto the fabric. It:
- Creates a smooth surface for printing
- Helps ink stay on top of the shirt, not sink in
- Improves print quality and durability
Pretreatment is especially important when printing on dark garments or using white ink.
🎨 Light vs. Dark Shirts: Do You Always Need Pretreatment?
| Shirt Color | Pretreatment Needed? | Why? |
|---|---|---|
| Light Colors | Optional (light coat) | Helps improve sharpness and avoid bleeding |
| Dark Colors | Required | Needed for white ink to bond properly |
💡 For light shirts, you can sometimes print without pretreatment, but the result won’t be as sharp. For dark shirts, you must pretreat, or the ink won’t stick well.
🛠️ Easy Step-by-Step Pretreatment Process
Step 1: Prepare the Shirt
Make sure the shirt is clean. Remove dust or lint using a roller.
Step 2: Spray Pretreatment Liquid Evenly
To get consistent results, use a pretreatment sprayer that distributes liquid evenly across the fabric. For higher precision, especially in commercial settings, an automatic pretreatment sprayer can save time and improve accuracy.
Step 3: Dry the Pretreatment
The drying process must use accurate temperature control. We recommend using a flat heat press to dry the pretreatment layer fully. Winnerjet’s DTG heat press provides stable pressure and heat, which helps prevent over-drying or under-curing.
Step 4: Spray the Pretreatment
- Use a sprayer or pretreatment machine.
- Apply evenly across the print area.
- Don’t overspray — use about 20–25g per print area.
Step 5: Heat Press to Dry
- Press the shirt at 160°C (320°F) for 30–40 seconds
- Use medium pressure
- Place a Teflon or parchment sheet on top
- The shirt must be completely dry before printing
⚙️ What Equipment Do You Need?
- Pretreatment Machine or Spray Gun – For even coating
- Heat Press Machine – To dry and flatten the shirt
- Lint Roller or Air Blower – To remove dust
- Protective Sheets – To avoid scorch marks
If you’re just starting, a manual sprayer works fine. For large jobs, an automatic machine saves time and gives more consistent results.
🧴 How to Choose the Right Pretreatment Liquid
The liquid you use depends on the shirt and ink:
| Fabric Type | Ink Type | Pretreatment Needed |
|---|---|---|
| Light Shirt | CMYK only | Light or none |
| Dark Shirt | White + CMYK | Strong pretreatment |
Winnerjet offers pretreatment solutions for both light and dark cotton shirts. If you’re unsure, try a sample and test your print quality.
💡 Pro Tips to Improve Pretreatment
- Don’t overspray the pretreatment — it can lead to stains.
- Always test compatibility with different fabric types. For example, Winnerjet’s DTG Pretreatment for Dark Shirts is ideal for strong white ink adhesion.
- Use a press with a built-in timer and even heat, like Winnerjet’s Pro Heat Press.
✅ Final Thoughts
Pretreatment may seem like an extra step, but it makes a huge difference in DTG printing. It improves color, sharpness, and durability, especially for dark garments. By following the simple steps above, you can avoid common print problems and get better results.
Need help choosing a pretreatment liquid?
👉 [Contact Winnerjet] or request a free sample to test before buying.
📋 FAQs: Pretreatment in DTG Printing
Can I skip pretreatment on white shirts?
You can, but the print might look dull. A light mist improves results.
Why is my shirt getting yellow marks?
Too much pretreatment or heat. Use less liquid and check the press time.
How long can I wait to print after pretreating?
Print within 24–48 hours. Longer delays can affect ink bonding.
What happens if the shirt isn’t dry?
Wet shirts will cause the ink to blur or not stick properly.
Is polyester suitable for DTG?
Not really. DTG works best on cotton. Try DTF or sublimation for poly fabrics.
