Screen printers debate which is better: plastisol or water-based ink. Some printers start out with plastisol ink, while others opt to jump right into water-based printing. But how are they different? Why would you use one over the other? Ink master Colin Huggins lays out the differences and nuances to printing each type of ink. You’ll be able to decide which ink is best for your shop.
Photo by Golden Press Studio
WHAT IS PLASTISOL INK?
Plastisol ink is essentially liquid plastic. It is easy to move at room temperature, and cures painlessly. Plastisol is the dominant ink of choice because it is user friendly. It doesn’t evaporate. You can leave the ink on the screen overnight and continue printing the next morning with no issues.
Plastisol also has a high opacity. The ink covers the shirt color well and is more forgiving with mistakes. If needed, you can cover up a mistake with another pass.
Photo by Symmetree Clothing
WHAT IS WATER-BASED INK?
Water-based is an up-and-coming ink in the screen printing world. The primary type of water-based ink we’ll be talking about is high-solids (HSA) ink, like Green Galaxy. HSA water-based ink provides a softer feel and is widely considered better for the environment and your shop.
Water-based ink lays down a thin, soft, flexible layer of ink on the garment. You can print a thin ink deposit that will still hold up after countless washes. When you’re finished printing, you can clean up with water or a similar cleaning product like Sgreen® Aquawash. Thanks to the little to none chemical usage, you’re able to reduce your eco footprint.
Printing with water-based inks isn’t a walk in the park. Since water-based inks contain water, the ink begins to evaporate once it’s exposed to air. If you take a break, wipe off the image area before you walk away. Be conscious of your time and energy.
WHAT ARE THE DIFFERENCES?
While the inks do have many differences, they are alike in some ways. Both types of ink are capable of the same amount of detail. The equipment needed to print each ink type is also primarily the same (more on that later). The main differences between water-based and plastisol ink appear in the darkroom, on press, and post-production.
How well you expose your screen directly impacts how well your screen holds up on the press. It’s always important to burn your screen properly, but water-based ink is a little more particular. First, you need to use an emulsion that’s water-resistant like Baselayr Complete or Long Lasting. Once you select the right emulsion, your exposure and drying process needs to be dialed. Otherwise, the water-based ink will cause it to break down during your print run. If you’re doing a large run with water-based ink, you’ll need to either use an emulsion hardener or post-expose.
With plastisol ink, the emulsion does not need to be water-resistant. While it’s still important to have your darkroom and processes dialed, plastisol is not as abrasive as water-based inks. The better the screen is, the less likely you’ll run into issues on press.
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As mentioned earlier, the supplies and equipment you use for printing with water-based vs. plastisol ink is pretty much the same. You’ll still need a press, emulsion, scoop coaters, squeegees, etc. The only difference in equipment is the curing device.
Plastisol is easy to cure. Heat from the bottom to the top of the ink layer, reaching fusion temperature (anywhere from 260-320℉, depending on the ink). Once that temperature is reached, you’re all set. Flash dryers, heat presses, or conveyor dryers work for curing plastisol inks.
With water-based inks, curing is a little more tricky. HSA water-based ink cures at 320℉. First, you need to evaporate all the water. If you don’t evaporate all the water, you cannot cure the ink. Once all the water has evaporated, the remaining ink layer (the resins in the ink) need to reach the recommended cure temperature and hold at that temp for a minimum of 20 seconds. For Colin, a water-based print takes one minute and forty-five seconds in a forced air conveyor dryer for it to be evaporated and cured properly. It’s definitely not the simplest process. Even if you have a gas dryer, it is still recommended to cure for 1:30 - 2:00 depending on your heat settings and dryer load capacity.
If you don’t have a conveyor dryer capable of this, adding Warp Drive to your ink will guarantee a full cure. Warp Drive works by chemically curing ink over 48 hours once the water evaporates.
You can also use a heat press to cure water-based inks. Set the heat press at 330 degrees with light to medium pressure. Place a teflon sheet on the print. When curing a water-based print, the ink layer needs to breathe in order to evaporate the moisture. Hover the heat press right above the print to let the heat evaporate the water content. Once it is dry, press onto it for 30-45 seconds. If you add Warp Drive to the ink, press it for 20-30 seconds and set it off to the side to let it finish chemically curing the ink.
RELATED: ENSURING PROPER INK CURING
THE FINISHED PRODUCT
Water-based inks are typically matte inks. They don’t have much gloss to them. Plastisol inks are usually semi-gloss/gloss inks. Water-based ink is smoother than plastisol. It can even be slippery based on the additives you use.
Plastisol ink is thicker than water-based ink. It will raise up above the shirt a little more than water-based ink will, creating more dimension to the print. Plastisol ink also is more rigid compared to water-based ink. If you scrunch up a garment, plastisol ink will feel more stiff.
Photo by Golden Press Studio
Water-based inks can be cleaned with water, or with a cleaning agent like Sgreen® Aquawash. If you’re printing plastisol ink, you’ll need to get your hands on an eco-friendly, oil-based cleaner, such as Sgreen® Supreme Wash or Ink Degrader.
WHICH INK SHOULD I USE?
It completely depends on what your customers want and your setup. If a customer is looking for a super soft print, water-based ink is the way to go. A client looking for a super bright print? Time to break out plastisol ink.
If you’re brand new to screen printing, you might want to start off with plastisol ink since it’s easier to use and cure. Plastisol ink is less aggressive than water-based ink, so your screen will hold up better if it wasn’t burned perfectly. Cleanup will be more of a hassle, but it’s all part of the process.
If you have the right equipment, water-based ink can work for you. If you’re dead set on using water-based ink but don’t have a heat press or forced air conveyor dryer, use Warp Drive. You do have to set the shirts off for 48 hours for the ink to reach cure, but it’ll ensure the ink won’t wash out.
Photo by Salt & Pine Co.
Ultimately, choose the ink that works best for your shop and your customer requirements. Both inks are great and can produce awesome results. Test out inks, play around with them, and you’ll discover which is right for you.