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If you’ve ever dabbled in screen printing, you know the magic really happens after the ink hits the fabric. But wait—before you start stacking those freshly printed shirts or tossing them in the wash—you’ve got one crucial step left: curing the ink.
Learning how to cure screen printing inks properly can make or break the quality and longevity of your prints. And no, waving a hairdryer at your shirt and calling it a day won’t cut it (unless you’re printing on dreams and hope). So let’s walk through everything you need to know to cure screen printing inks like a pro.
What Does “Curing Ink” Actually Mean?
Curing is the process of applying heat to your printed design so the ink fully sets (aka bonds permanently) to the fabric. Without curing, your prints might crack, fade, or wash out entirely. Curing is what makes your ink go from “meh” to “merch-worthy.”
Different types of inks require different curing methods, and temperatures matter—a lot. Let’s dive into how to cure screen printing inks the right way.
Types of Screen Printing Inks & How to Cure Them
Before we fire up any heat sources, let’s get familiar with the two main types of inks used in screen printing:
1. Plastisol Ink
Plastisol is the most common ink used in screen printing. It’s thick, vibrant, and sits on top of the fabric. But it doesn’t dry unless heat is applied.
Curing Plastisol Ink:
- Curing Temperature: 320°F to 330°F (160°C to 165°C)
- Curing Time: 1 to 3 minutes, depending on the heat source
2. Water-Based Ink
Water-based inks soak into the fabric, giving a softer feel. These inks require more precision when curing, as they need to evaporate the water content and set the pigments.
Curing Water-Based Ink:
- Curing Temperature: 300°F to 320°F (149°C to 160°C)
- Curing Time: 2 to 3 minutes
Note: Curing water-based inks without proper airflow can lead to under-cured prints.
Tools You Can Use to Cure Screen Printing Inks
Now that we know the target temps and times, let’s talk gear. You don’t need a full-on industrial setup to start curing inks properly, but using the right tools makes a big difference.
1. Flash Dryer
Best For: Small shops and semi-pro setups
Flash dryers are built for curing. They offer consistent, even heat across the print area. Just keep the head a few inches above the shirt and rotate if needed.
2. Conveyor Dryer
Best For: High-volume production
This is the Cadillac of curing equipment. Shirts go in one end, fully cured garments come out the other. It’s expensive, but worth it if you’re printing in bulk.
3. Heat Gun
Best For: Small prints or touch-ups
A heat gun is affordable and portable, but it can be inconsistent. You’ll need a thermometer or heat strips to ensure you’re hitting the right temperature.
4. Home Oven or Heat Press
Best For: DIYers or beginners
Yes, you can use a heat press or even an oven in a pinch. Just make sure the ink reaches the required temperature without scorching the fabric.
Step-by-Step Guide
Ready to get hands-on? Here’s a step-by-step guide on how to cure screen printing inks for both plastisol and water-based varieties.
Step 1: Let the Ink “Set”
After printing, allow the ink to air dry for a few minutes. This reduces the risk of smearing when you move the fabric.
Step 2: Preheat Your Curing Tool
Whether you’re using a flash dryer or heat press, let it warm up completely. Use an infrared thermometer to check the surface temp.
Step 3: Apply Heat
Position your heat source a few inches above the ink. Keep it moving (if using a heat gun) to avoid burning. For plastisol, you’ll notice a slight gloss when it’s fully cured. Water-based inks will lose their shine.
Step 4: Check the Temperature
Use a laser thermometer or heat-sensitive strips on the print. You must hit the recommended curing temperature for the ink to fully set.
Step 5: Wash Test (Optional)
After curing, wait 24 hours and then wash the garment. If the print cracks, fades, or peels, you likely under-cured it.
Pro Tips for Perfect Ink Curing
- Don’t rush it. If you’re in a hurry and under-cure the ink, your print won’t last.
- Avoid scorching. If your fabric smells like burnt toast, back off the heat.
- Test often. Always test new inks or fabrics before doing a full run.
- Keep a thermometer handy. Guessing = regret.
FAQs
Q: Can I air-dry screen printing inks instead of curing them?
Nope. Plastisol won’t cure without heat. Water-based inks might dry to the touch, but without curing, the print won’t last through a wash.
Q: How do I know if my ink is fully cured?
The best way is a stretch test (gently stretch the print—no cracks means it’s likely cured) and a wash test (wash it and see if it holds up).
Q: What happens if I over-cure the ink?
Over-curing can cause ink to become brittle or discolor. It might also scorch the fabric. Always monitor your curing process closely.
Q: Can I use an iron to cure screen printing ink?
Technically yes, but it’s not ideal. It’s hard to reach consistent high temps with an iron, and uneven pressure can ruin the print.
Q: How long should I cure screen printing inks?
It depends on the ink and heat source, but generally 1 to 3 minutes at the right temperature will do the trick. Always follow your ink manufacturer’s guidelines.