Plastisol is one of the most commonly used inks in screen printing, but just because you use it every day doesn’t mean you know everything about it. To help separate fact from fiction, here’s a quick guide to understanding what plastisol is, when to use it and how to get the best results.
Q: What’s plastisol ink?
A: Made with PVC (polyvinyl chloride), plastisol ink isn’t water-soluble – in fact, it contains no solvent at all. It’s often referred to as a 100% solid ink system. It’s also thermoplastic, meaning printers must apply heat for the molecules of PVC resin and plasticizer to cross-link and solidify, or cure, according to a fact sheet written by Mike Ukena of the Printers’ National Environmental Assistance Center. In general, plastisol curing temperatures range from 300° to 330° Fahrenheit.
Q: When should you use plastisol ink?
A: Plastisol is versatile, easy to manage and user-friendly, according to Ryonet Corp. (asi/528500). Usually, it’s ready to use out of the container. There are plastisol inks formulated for most fabric types, including nylon, polyester and cotton. Printers may need to use an underbase on certain garments, particularly with dark colors, to help prevent dye migration. The garments you choose must be able to withstand the heat required to cure plastisol. A fabric with the potential to melt wouldn’t be a good candidate for plastisol printing.
Q: How do you ensure your ink has been cured properly?
A: There are two widely accepted methods of testing plastisol ink for a proper cure. The most popular, according to Lawson Screen and Digital Products, is the stretch test. This is what the name implies – stretching the garment to two-thirds of its total elasticity. “If the print cracks and doesn’t retract when the fabric is released, the ink is probably under-cured,” according to Lawson’s website.
The second test is the ethyl acetate test, where you add a few drops of ethyl acetate to the underside of a plastisol print, according to Lawson. Then, press the fabric treated with the ethyl acetate against a portion of fabric containing no ink. If the ink transfers to the blank fabric, the print isn’t properly cured.
Q: What mesh count should you use with plastisol?
A: Most ink manufacturers recommend mesh counts for the inks they sell, and getting the best print requires paying attention to this information. The characteristics of the ink and the print will determine the mesh count. Here’s a quick rule of thumb: 110-count mesh is popular for white and other light-colored fabric, and 156-count is often used for black, according to Ryonet. The 156-count mesh holds more detail than 110, but less ink will pass through the screen. One benefit of plastisol is that it can be left in the screen for extended periods of time without clogging the mesh, as Ryonet’s website notes.
Q: What are some fun things you can do with plastisol?
A: Printers can create unique prints, using special-effect plastisol. There are glow-in-the-dark inks, glitter inks and other additives that give prints a distinctive look or hand. Among the manufacturers that offer special-effect inks are Wilflex, One Stop Inks, International Coatings and Atlas Screen Supply Co. When using a special-effect ink, be sure to follow the manufacturer’s recommendations for mesh count and fabric choice. Most specialty inks require a mesh count between 24 and 86, according to Ryonet.
In this video, Ryonet CEO Ryan Moor gives a brief overview of plastisol and how it has affected the industry.