You may have been perusing the market, looking for inks that’ll help you print on polyester materials like a pro. Have you noticed that there are a few types of polyester inks like dye blocker ink and Poly White ink? What’s the point? Do you need both? Can you get away with having one or the other? Let’s take a deeper look at dye blocker inks and Poly White inks to see what roles they play in screen printing.
Before jumping in, let’s quickly go over a few terms. Dye migration, also known as bleeding, happens when dye from polyester fabrics transfers into the ink on a printed shirt. It can occur either immediately after curing (dye sublimation) or gradually over time. This issue affects colored polyester and poly/cotton blend shirts, including tri-blends and 50/50 blends, but not white polyester. Dye migration occurs when the garment is heated between 260°F and 340°F, causing dye in the fabric to sublimate and mix with the ink. While both water-based and plastisol inks can experience this, plastisol ink is more susceptible. To learn more about dye migration, check out this article.
Sublimation happens when the dyes are activated by heat, causing them to be gaseous and enter the ink. If you notice discoloration in a print when it comes out of the dryer, it’s dye sublimation. If discoloration appears in the ink over time, that is dye migration.
Printers want to avoid both dye migration and dye sublimation at all costs. So, let’s take a look at the tools that help prevent these nuisances.
WHITE POLYESTER INK EXPLAINED
Poly White ink is formulated to be printed on synthetic fabrics like polyester. It contains high levels of bleed-fighting ingredients that slow down dye sublimation and migration over time. These ingredients make the ink durable, which is essential for athletic printing. Just be aware that it’s also a thicker ink compared to the average low-bleed white ink.
When printing on standard polyester garments, Poly White ink will do the trick (a low cure Poly White ink is even better). When curing Poly White prints, set the temperature of your conveyor dryer to a lower setting to avoid exciting the dyes in the fabric. The one-two punch of low temps in dryers and white inks with dye migration resistance properties makes printing on polyester garments simple.
But guess what? Not all polyester substrates are the same. Some are extra finicky and you may encounter bleeding.
Now, you’ll want to turn to a dye blocker ink.
WHAT IS A DYE BLOCKER INK?
A dye blocker ink is a specialized type of ink used to prevent dye migration. On the market, you’ll notice two versions of a dye blocker ink — gray and black. Both types have activated carbon, an element that helps inhibit the migration of dyes from the fabric into the ink.
So… What’s the difference between the two? Black dye blocker inks are filled to the brim with concentrated carbon, giving you the best chance to fight off pesky dye migration and sublimation. Gray is black and white ink mixed together. Both have concentrated carbon, but the black version has more. In extreme cases, a black dye blocker ink will outperform a gray dye blocker ink.
Now, this doesn’t mean you should solely use black dye blocker inks. Both work great! It completely depends on the quality and consistency of your conveyor dryer as well as the quality of the polyester material. For example, dye-sublimated material is well-known for being a tough fabric to print on. When using a similar fabric, you should use a black dye blocker. But, if you have a gas conveyor dryer that’s dialed to a T, then you may be able to get away with a gray dye blocker.
The only way to know is to perform several test prints and wash tests to confirm which is the best route to go.
As it has been alluded to, dye blocker inks are to be used as underbases. The dye blocker base will stop dye migration from affecting the ink and the colors you print on top of it. By using a dye blocker base as an underbase, screen printers can achieve more vibrant and accurate colors on polyester or poly-blended materials. Using a blocker base is especially important when printing on dark-colored polyester fabrics, as dye migration can be more noticeable.
Dye blocker bases are an essential tool in screen printing to ensure that printed designs maintain their intended colors and quality, particularly on challenging substrates.
But why are there several kinds of polyester inks? Let’s take a look…
WHEN SHOULD I USE EITHER INK? WOULD I EVER USE BOTH IN ONE PRINT?
As mentioned above, the type of polyester you’re printing on will determine which inks you should use. Again, if you’re working with especially challenging fabrics like dye-sublimated materials, you must use a dye blocker base.
Rule of thumb — use a dye blocker base and print a Poly White ink on top of it. It’s extra protection to ensure dye migration or sublimation doesn’t happen.
Every garment distributor has a list of ways and recommended inks to decorate the garments they sell. If you do not know, contact your vendor or the manufacturer and ask them what they have found in their testing
If you cannot get the information you need in your searches, then the only way to know for sure is through testing and possibly feedback from other printers.
If you’re unsure and you do not have time to test, use a blocker base to avoid any possibility of dye migration.