A Complete Guide on Curing Your Screen Printing Ink

Posted by Jeffrey Gononsky on

Screen printing can be a fun and exciting way for you to let your imagination shine by creating incredible custom designs on a wide variety of materials like shirts, sports equipment, glasses, and more. However, to create quality, long-lasting designs, you will need to take the proper steps to cure that ink so that it will last. 

How do you do that? Check out this guide below for all of the basics that you might need to begin the curing process of your screen printing journey!

What is Ink Curing?

Essentially, curing the screen printing ink on a fabric or other surface is making sure that the color isn’t going to move anywhere once you’ve completed your design. When you cure the ink, you’re heating it enough so that it adheres to the fibers of the fabric you’re working with, causing a chemical reaction to make the fibers bind to the different screen printing inks.

When you use screen printing ink on other mediums those also have to be cured to ensure the longevity of the design. This type of curing isn’t always going to be the same process as what you’d use when working with fabrics, but the essentials are all going to be similar: heating the ink to make sure that the design adheres to the medium you want it to. 

Why is Properly Curing Ink Important?

Without curing the ink, the pigment has no way to adhere to the surface of the product you’re trying to screen print. It’s almost like creating a painting but then not allowing the paint to dry before placing your hands on it or displaying it in your home.

Curing is extremely important because, without it, the screen-printed ink will not stick to the surface of your shirt or other material and will not have the longevity that you’d want from a finished product. Improperly cured ink causes the color to flake off or fade quickly, leaving you without a quality product. If you’re curing a shirt, then it allows the shirt to be washed multiple times without having the screen printing ink crack or fade.

The Curing Basics

When you begin curing, you’ll quickly realize that every process is just a little bit different. For curing screen printing inks on t-shirts, which is likely the most common item you’ll be curing, you’ll need to heat the fabric inks anywhere from 270-330 degrees Fahrenheit (depending on which screen printing ink you’re using) to ensure that the design will adhere properly to the shirt.

Water-based fabric ink typically cures at about 320 degrees and takes about three minutes to cure. Plastisol ink, which is essentially liquid plastic, cures at about the same temperature but typically only will take a minute or so. There are low-heat plastisol ink options that cure at about 270 degrees, but you should always double-check the packaging and product that you’re using before you begin working.

Curing with a Heat Gun

If you’re just getting started with screen printing or are only doing a very low volume of prints, a heat gun might be your best bet. Typically no more than 50 dollars, a heat gun is the most cost-effective way of curing screen printing ink. However, it is also the most unreliable and uneven. Using a heat gun to cure screen printing ink is going to take a little practice to make sure you’re getting it right.

A heat gun, while uneven and not quite as accurate as some of the other curing methods mentioned, works well because it’s able to get up to the temperatures that you need to cure the print. The temperature levels are typically around the 300-degree range. Just make sure that you don’t accidentally use the heat gun as a hair dryer!

There are a couple of things to be wary of if you’re using a heat gun as your curing medium. Because you don’t have the option of doing an even, all-over heat as you would with another method, you must be careful not to burn the fabric, wood, or other material you’re trying to cure. A heat gun is a single point of intense, concentrated heat, and if you aren’t careful, you could easily burn the product you’re working with. 

It is also extremely difficult to accurately measure the precise heat you’re getting when working with a heat gun, as there aren’t precise controls. If the heat on your gun is too low, then the ink won’t cure. If the heat is too high, then the ink may boil. Boiling the ink is especially dangerous when working with plastisol ink since plastisol ink is liquid plastic. 

Additionally, curing with a heat gun does not work for all screen printing inks. You shouldn’t use a heat gun with water-based fabric ink, because it needs extra additives to cure with this method. It can be done, but it will require extra steps and extra products.

There are other more reliable ways to cure screen printing inks, but here at Holden’s, we understand that everyone has a different budget, and that’s okay! We’re just happy that you’re interested in the amazing art that is screen printing.

Curing with a Heat Press

A heat press makes curing your screen printing ink much easier and much more accurate. Heat presses are more costly than a heat gun and might not be a viable option if you’re just starting out with screen printing in New York or elsewhere. However, a heat press tends to give better results without all of the hassles that come with using a heat gun.

A heat press gives a much more even temperature and allows you to apply pressure across the surface of the item you’re curing. Also, heat presses are more accurately able to measure temperature and will often have electronic temperature readouts to let you know precisely how hot it’s getting. 

Heat presses are a great choice for lower volume shops, as the press can only cure one piece at a time but is much more precise and reliable than a heat gun. 

There are a few extra steps to using a heat press as opposed to a heat gun, but the accuracy is worth it. When you are getting ready to use the heat press, you want to make sure that you place a barrier sheet (like Teflon) between the heat press and the design so that the ink does not adhere to the surface of the press. Let it cure for the time specified on your particular brand of screen printing ink, and you’re good to go!

Plus, unlike heat guns, heat presses can easily be used with water-based fabric ink without having to add any additional additives. Simply hold the heat press over the top of the water-based ink for a few seconds to help evaporate the water, then use the barrier sheet as mentioned before with the plastisol ink. This method gives you an even, accurate heat all the way across your design. 

Curing with a Flash Dryer

You’d be hard-pressed to find a screen printing pro who doesn’t know - or use - a flash dryer. Flash dryers tend to be a favorite among screen printing shops and hobbyists alike for their ease of use and accuracy. They’re simple to learn, so they’re a favorite among beginners. Plus, flash dryers can cover a large surface area, so curing often takes less time. 

Much like a heat gun, a flash dryer isn’t a press. Flash dryers use large bursts of intense, concentrated heat to accurately cure the screen printing ink. Unlike heat guns, however, you’re more easily able to control the temperature and have more accurate temperature readings as you work. 

To use a flash dryer, you must first consider the environment of the room around you. If your press is located in a colder room, that means that the screen printing ink is going to take longer to dry. Measure accurately!

Once you’ve determined the time and the heat needed, place the item to be cured onto a flat (preferably metal) surface and hold the flash dryer about three inches above the print. Aim at the center of the design and hold the flash dryer there for the appropriate amount of time according to the curing instructions on your screen printing ink. Once the time is up, your ink should be cured!

One thing to be aware of with flash dryers is that, much like heat guns, you cannot use flash dryers to cure water-based fabric ink unless you include the appropriate additives. It is not impossible to do so, but it requires additional steps. 

Curing with a Conveyor Dryer

A conveyor dryer is the biggest - and most expensive - curing method out of the bunch. A conveyor dryer is best used for high-volume screen printing orders, and it’s unlikely that you’ll see one of these outside of a brick-and-mortar screen printing shop. 

Conveyor dryers are easy to use. With these, it’s more of a “set it and forget it” kind of mentality. You place your item to be cured on one end of the conveyor belt, input your settings onto the machine, and watch your item go through the conveyor. When your item is done curing, it pops out on the other side!

It’s also helpful to note that conveyor dryers can cure water-based ink if the dryer used offers air circulation. If the conveyor dryer doesn’t have any kind of forced air circulation, then you may still need an additive to the water-based ink to ensure it adheres to your print. 

Other Tools that Might Help

With most curing methods and tools, you’re able to get an accurate temperature reading to ensure that you’re abiding by the ink’s curing instructions. With some tools, like a heat gun, it’s more difficult to get a precise reading. That is where a laser temperature sensor might help!

A laser temperature sensor is a thermometer that, when pointed at a heat source, can accurately measure the temperature. This is extremely useful when working with tools that don’t give you an accurate or precise reading and can be a handy extra tool to add to your screen printing arsenal.

Another thing that is immeasurably helpful and every screen printer should have at their disposal is other screen printers! Go on a hunt for local screen printing businesses or hobbyists to see if they have the curing tools you need and will be willing to let you borrow (or rent) them. If you’re working in screen printing in New York, for example, don’t be afraid to ask others who also work in screen printing in New York for advice, examples, or the use of their equipment. They can be life savers!

How to Test if Your Ink is Cured

Once you’ve cured your ink, there are several easy tests to see if your design has cured properly. 

First is the stretch test. When your ink has cured, gently tug on the fabric to see if any kind of cracks or breaks appear. Don’t tug it too hard; you only want to tug it enough to see if anything immediately happens to the ink. If the print cracks and flakes when you tug on the fabric, then it isn’t cured properly.

Another easy test to do is the wash test. It is as simple as it sounds: wash the item several times to make sure the ink doesn’t fade. If the screen printing ink isn’t fully cured, then the print will begin to fade after the very first wash.

Don’t be afraid to do multiple test runs to ensure that your screen printing ink has fully cured! It will likely take a little finagling before you’re able to get it just right. 

Curing Ink on Other Surfaces

While this guide primarily focuses on fabric curing, other items need to be cured when working with screen printing ink. 

Glass and ceramic can sometimes be tricky. Instead of the above methods, kiln firing is typically the best method to use for curing screen printing ink on glass and ceramic surfaces. However, finding a kiln can be difficult at the best of times, and isn’t always a viable option. If kiln firing isn’t an option to cure your glass, heat guns work very well for this application.

Surfaces like wood can actually be cured following the same methods listed above The most important thing to remember about curing wood is to make sure that you don’t burn the material itself. That could be catastrophic for your item, your business, and potentially yourself. 

How Holden’s Can Help

Here at Holden’s, we pride ourselves on offering you quality screen printing supplies to help you create the best possible projects. If you’re interested in trying some of our incredible screen printing supplies, then check out our website today!