Sometimes you need to print on stretchy fabrics. Think leggings, jerseys, athletic clothing, and more. Stretchy clothes are likely to have Spandex, or Lycra, in them. In order to print on ultra-stretchy garments with plastisol ink, you’ll need a special tool in your arsenal: FN-INK™ Stretch. Let’s talk about everything you need to know to print on Spandex and Spandex-blended garments.
WHAT YOU’LL NEED
Since these fabrics are stretchy, you’ll need a stretchy ink to make sure the print holds up well. Plastisol ink stretches to a point, but you’ll need extra stretch to allow that print to live up to its full potential. Think about what the garment is going to go through during its lifespan. Will it be put under a lot of stress? If so, you’ll need a stretch ink.
Depending on the garment you’re using, you might want to include a blocker base. Garments made with 100% Lycra won’t bleed or cause dye migration, but blends can (more on this later). A blocker base like Barrier Black will do the trick and help to stop dye migration.
Now that we’ve assembled the specialty inks necessary for the job, let’s talk about garment fabric content.
FABRIC CONTENT MATTERS
It’s no secret that fabric content is important when screen printing. Different blends and fabrics can produce a completely different feel of print and require different printing techniques. Many fabrics may be blended with Spandex. Cotton, for example, can have Lycra blended in it to create a super-stretchy cotton shirt.
When printing with these types of fabrics, always check the fabric content of the garment you’re printing on before you head to production. As we mentioned before, 100% Lycra will not bleed, but other blends could. Say you’re printing with a Lycra/Polyester blended garment. Typically, Lycra is added at 5-10% for added stretch. That means the garment is mostly Polyester. You know what that means: dye migration.
Once you’ve checked out the fabric content of the shirt and made a plan, it’s time to get printing.
If you have a blended garment that’s likely to experience dye migration, you’ll need to first lay down that blocker base layer to prevent dye migration from the fabric into the ink. However, if you’re looking for tons of stretch, Barrier Black won’t do the trick on its own. So what do you do?
Add FN-INK™ Stretch to Barrier Black to solve this problem. Be careful of the amount of FN-INK ™ Stretch added to the blocker base, though. Add too much and you’ll reduce the blocking properties of Barrier Black. The best thing to do? Add some stretch ink to the base and test. It’s all about how the inks and dyes behave based on the garment you’ve chosen.
Once you’ve printed a solid dye-migration blocking layer, print with FN-INK™ Stretch. You can print stretch multiple ways. If the garment isn’t going to be stretched too much, add FN-INK™ Stretch into colors up to 25% by weight. For more stretch, add it to the base white up to 50% by weight.
Want maximum stretch? Print FN-INK™ Stretch by itself as an underbase. You can add stretch ink to the colors of your print as well for ultimate stretchiness. Think about how much the garment will stretch over its lifetime and add FN-INK™ Stretch accordingly.
Now, it’s time to cure.
CURING SPANDEX GARMENTS
Spandex and Spandex-blended garments can be a little tricky to cure. For starters, the dyes in these types of garments are set at different temperatures. Take poly-blends, for example. Dyes are set in garments around 270°F-300°F. When the polyester thread hits that temperature range again, the dyes return to a gaseous state and are absorbed by the plastisol inks.
Certain colors of dyes in Lycra or Spandex—like fluorescent colors—are heat sensitive, while others are stable up to 375°F. It’s great to have a low cure ink like FN-INK™ already since it hits full cure at 260°F. As a rule of thumb, keep temperatures in the conveyor dryer as low as possible while still hitting cure temp of 260°F. Testing is super important when printing on Spandex, especially when the Spandex is blended with other materials.
When printing on Spandex or Spandex-blended garments, fabric content matters most. Make sure you have what you need to print on the shirt you’ve chosen successfully. This process may take some experimentation, but with a little patience and some testing, you’ll be able to nail it.