The ink that most of us are familiar with for screen printing is plastisol. Plastisol is cheap, easy to use, and it delivers great results. One of the other major options for inks is water based inks.
Water based inks, as the name implies, are solutions of chemicals and dyes with water is the main solute. The term doesn’t imply that water is the main agent in the ink, only that it is the largest ingredient therein.
Water based inks differ from plastisol in a few ways.
Specialty Prints: Discharge inks, which change the color of the substrate and add their own pigment, are water based inks. The quality of such prints and the soft hand of the prints lends them to printing “vintage” shirts, a popular effect.
Softer Hand: This term comes from the most common method of measuring the feel of an ink: hands. When you run your hand over a shirt printed with plastisol, you can feel the ink. It sits on the substrate. Water based inks are tactilely indistinguishable from the substrate. It’s a much more natural feeling.
Longer drying time: Water is the medium that delivers the active agents of the ink to the substrate and must be completely evaporated before the next screen step or shipping. The drying process is a little more intricate for water based inks, since the ink has to remain at a constant temperature until the ink is completely dry. Flash curing is not an option in this case. Instead, a large dryer, a sort of industrial size oven, is used to bake the water out of the ink.
Environmentally friendlier: Let’s set the record straight: Use of the word friendlier is pretty poor English, but an accurate one in this case. Most inks have some sort of negative environmental impact, but water based inks minimize environmental impact. Lest you picture woodland creatures frolicking in water based inks, we’re still talking about some pretty powerful chemicals. Some water based inks contain some intense organic compounds that go airborne in the drying process. Adequate ventilation is required.
Harder on equipment: Though they take longer to dry in production, water based ink dries in a hurry when printing. You can’t let it sit in a screen like plastisol. It clogs screens and equipment quickly, which is bad news for lazy printers.
Longer production time: As you can imagine, the extended drying process between screens increases run time. A lot. Plastisol cures very quickly, and in some cases, you don’t need completely dry plastisol before the next screen. The longer run time equates to higher expenses for you.
Fabric Type: Water based inks only work on 100% cotton. Water based ink is more of a dye than an ink. It must be absorbed into the fabric to work, and thanks to the water repelling characteristics of polyester, there is no absorption on polyester and polyester blends.
Water based inks are great choices for people who are looking for a very particular quality to their shirts, or who are willing to pay a little more to lessen their environmental impact. If you feel strongly about using water based inks for your next print job, talk with the customer service folks at DFC to see if that makes sense for your design and to your bottom line.