What’s the Difference Between Plastisol and Water-Based Inks?

Are you a screen-printing enthusiast or t-shirt shop owner looking to take your print game to the next level? We’ll drill down into plastisol and water-based inks, so you can learn their fundamental differences – their unique characteristics, application methods and environmental impact. We tackle five commonly asked questions about these two types of screen-printing inks, so you can unlock the keys to achieving vibrant, long-lasting designs that match your artistic vision!

Let’s start with the basics, by defining plastisol and water-based screen-printing inks. Plastisol ink is a PVC-based solution that doesn’t contain a solvent – you’ll sometimes hear it referred to as a 100% solid ink system. Plastisols are thermoplastic inks, which means that you need to heat or “cure” the ink at a high-enough temperature to force the PVC resin and plasticizer molecules to solidify. The temperature for curing most plastisol inks on garments and textiles ranges from 300 °F to 330°F.

Water-based inks use either dyes or pigments in a suspension with water as the solvent. To cure or set the ink, the water needs to evaporate. The curing can occur at room temperature or with a forced-air dryer. The curing method you choose will depend upon the water-based ink type and how quickly you need to process shirts.

Printers widely favor plastisol ink because it adheres well to a wide variety of fabric types, including polyester, cotton and nylon. Here are some other advantages of working with plastisol:

• It’s a user-friendly ink. The creamy and thick consistency of plastisol ink, derived from resins, pigments and plasticizers, almost guarantees an effortless application. If you’re new to screen printing, it’s best to start with this ink type. Generally, you can also use plastisols right out of the container, without needing to adjust the viscosity or the strength.
• It gives you an accurate color match. You’ll easily match any Pantone color with plastisols. Plus, you can accurately match your ink colors on any fabric color or type.
• It creates vibrant prints: This ink type creates vibrant and durable prints that withstand the test of time, without cracking, peeling, or fading, regardless of whether you apply them to light or dark shirts in any color.
• It won’t clog your screens. If you leave plastisol in your screens for an extended time, it won’t dry in your mesh – so you can easily clean the screens. Plus, you can put any unused inks back into your container to reuse for another job, saving you money and needless waste. 
• It facilitates a faster printing process. Plastisols can usually be printed wet-on-wet, saving you time during the application.
• It’s available in many varieties. Many reputable brands carry plastisols in different strengths, from opaque to transparent, so you’ll have everything you need to produce amazing designs in your ink supply cabinet.

Here are some of the downsides to working with plastisols:

• It’s not as breathable. If you want to maintain breathability on your t-shirt surface where you’ve applied the ink, avoid using plastisols. These inks give you vibrant colors and crisp lines, but this synthetic PVC ink can coat the fabric's surface, reducing its breathability for wearers during physical activity.
• It may melt under high heat. Since plastisol is a thermoplastic, it might melt or smear if it gets too hot, like under an iron or even in a dryer cycle that’s too hot.
• It has a discernible “hand.” Many buyers don’t like a large, heavy ink design that feels coarse when they touch it. The higher your ink’s opacity, the heavier it feels.
• It’s harder to discard. We recommend checking with your local regulatory agency for guidelines on getting rid of cured or uncured plastisol inks. The chemicals that you use to emulsify the ink to remove it from your screens, squeegees, flood bars, other tools and work surfaces also pose an environmental hazard, so you need to learn how to dispose of it properly.

Here are some advantages of working with water-based inks:

• It might be more eco-friendly: Printers consider water-based inks to be “more” eco-friendly than plastisols, since they’re not made with harmful chemicals like phthalates and PVC like other inks. However, since they’re water soluble, you won’t need harsh chemicals to clean them up.
• It creates a soft hand. These inks produce vivid, soft, lightweight prints on lots of fabrics, like cotton, polyester and rayon – which consumers look for and love to wear because of the comfort and breathability. Unlike plastisol inks, water-based inks absorb into the fabric, rather than sitting on top. If you want the feel of retro or vintage artwork, water-based inks are your go-to.
• It “penetrates” thicker fabrics. If you’re printing fabrics like towels with a high-nap fabric, water-based inks wick to the base fabric for total coverage. Because the inks “sink” into the fabric, many decorators report that they last longer than plastisol inks, which can crack, peel or fade over time.

Here are some of the things to consider when working with this type of ink, which can be more costly than plastisols:

• It isn’t totally eco-friendly. Many water-based inks contain petroleum-based co-solvents, besides water. However, many printers still consider them to be less harmful to the environment than plastisols, which use fossil fuels like petroleum to manufacture.
• It might be harder to color-match. While water-based inks will produce accurate colors, they do best on white or light-colored cotton garments. It’s harder to match shades on different fabric types and colors.
• It can clog your screens. Remember that these inks contain a water-based solvent that evaporates? If you leave your ink in your screens for even a short time, it can dry and then clog the mesh and ruin your screens. You’ll also need to specially coat your screens to work with water-based, and then clean them afterward.
• It doesn’t cure as easily. These inks are harder to cure than plastisol. If you decide to use water-based inks, you need to have a way to dry the inks and remove the water. Plastisol inks cure quickly when heated to the right temperature. Water-based needs to reach the right temperature and keep curing until all the water is removed. Some printers add a catalyst to the ink that helps the ink cure completely after coming out of the dryer. You can’t use this mixed ink after four to 12 hours from mixing it, so you have to discard any extra.

Pro tip: If you want those water-based inks to stick nicely to your poly-cotton or tri-blend t-shirt, make sure it has a higher percentage of cotton. And if you're aiming for a really eye-catching screen print, adding a base layer of ink can do the trick. But here's the deal: when it comes to darker fabrics, it's best to avoid using water-based inks. Why? Well, they tend to get soaked up by the fabric and hide your awesome designs. To make sure your designs pop, go ahead and use a base layer.

Many decorators enjoy working with both plastisol and water-based inks, depending on the design, fabric type and effect they want. Plastisol ink is perfect for vibrant and accurate colors on any shirt shade – which is great for a company, event or band that requires an exact color match. Water-based ink is ideal for soft, lightweight designs, so they’re great for fashion items, work garments to be worn outdoors or for working out. Try out both and see where your creativity takes you!

With Clothing Shop Online's (CSO) affordable collection of stylish t-shirts, hoodies, hats and bottoms in different colors, fabrics and fits, you can add a lot of personality to your wardrobe or the pieces you’re decorating to sell with screen printing. Shop CSO's t-shirt styles, hoodies and headwear for men, women and youth. They’re great for decorating with graphic or text-based designs and wearing everywhere. After all, your new apparel and accessories are your blank canvas for your creativity and self-expression.