Recently I've been using Permaset Supercover inks for screen printing. I like how they feel on the garment and are a breeze to wash up. But curing the ink has proven a bit difficult for me until now. The pros recommend using a tunnel dryer but if you're like me and have a small home-based operation, there really isn't room or $$$ for a tunnel dryer. Here's what I've learned about curing water-based ink with a heat press.
Make sure garments are completely dry
I usually let my garments air dry for at least two days days before curing them. Permaset also mentions drying them in the dryer for 30 mins which could work if you're in a hurry. If you don't get all of the moisture out of the garment before curing, the ink can't heat up to the correct temp and it won't cure properly.
Use a temperature gun
I bought my heat press on eBay. It was super cheap and had no instructions. I thought all it had to do was heat things so how hard can it be? Well, it turns out that the temperature gauge and the actual temperature of the press were two different things. It was off by about 60°F. The way I found out was by buying one of those temperature guns and aiming it at the heating plate. So I now use the temperature gun reading to set my heat press and not the temperature gauge.
Check the temperature of the ink
Permaset recommends curing your ink at 320°F for 2-3 minutes. I found that if my heat press is set to 320°F, the ink will not heat to the same temp. I checked this by aiming my temperature gun onto the ink right after opening the press (do it quick! it cools down immediately). So I ended up raising my heat press temperature a bit higher to get the ink to the correct temperature. As you raise the temperature, keep an eye on your garment to make sure it doesn't singe. I also recommend covering your garment with teflon sheets when curing for further protection.
Light-colored shirts need a lower temp
I found out that with light-colored shirts (such as heather gray) discoloration will occur at higher temps. For light-colored shirts, I use the lowest possible temp (248°F for 8-9 minutes) and cure the shirt inside out with a teflon sheet on top.
Experiment, Experiment, Experiment
Every heat press is different. There is no one fail-safe setting. But if you take the time to experiment, you should be able to come up with a system that works for you.
Wait 24 hours before doing a wash test
I've had the best luck when I wait at least 24 hours (usually 48) before washing a cured garment. That way the ink "sets" and is less likely to crack or come off in the wash.
I hope this helps! And happy curing!