What Is Dye Migration and How to Prevent ItBy ShirtSpace | Aug 23, 2019 | Updated Aug 15, 2023
Whether you’re new to screenprinting or have been in the industry for years, it’s a good idea to familiarize yourself with dye migration. Learning what it is and how to prevent it will save you botched jobs and future headaches.
Dye migration occurs when dye from polyester fabric bleeds into the ink that is screenprinted on the garment. An example of this is white ink that turns pink after having been printed on a red polyester t-shirt.
What causes dye migration?
Curing ink requires using heat. The problem at hand is that both plastisol and water based inks must be cured at 320-330 degrees to prevent the ink from washing out when laundered, but when polyester fibers reach 280 degrees the dye from the fabric can begin to bleed into the ink. What’s worse, is that dye migration can occur several days after printing so it won’t immediately be visible.
How do you prevent it?
1. Print with specially formulated dye blocking polyester inks or low cure inks
Ink manufacturers are well aware of dye migration and have formulated inks that are specifically designed to print on polyester fabric. Some of these inks cure at a lower temperature so that you don’t have to worry about reaching 320 degrees, while others are formulated using dye blocking characteristics and cure at the standard 320 degree mark. Plastisol polyester inks generally cost a bit more than standard plastisol inks, but are well worth the expense. At this time we aren’t aware of waterbased polyester inks, but hopefully they’re on the horizon!
2. Use low cure additive
Low cure additive is used to reduce the curing temperature of both plastisol and waterbased inks. You simply add your additive to your ink based on the manufacturer’s instructions, mix it up, and print.
3. Print a white underbase
For those that are new to the game, a white underbase is when a white layer of ink is screenprinted, flash cured with a flash dryer or heat gun, and another layer of color ink is printed on top. Printing a white underbase on dark garments is a widely used screenprinting technique that’s a great way to achieve bright colors, and when printing on polyester garments, can prevent dreaded dye migration.
Printing a white underbase using dye blocking polyester ink that cures at 320 degrees allows you to print your base, flash cure, and print standard plastisol ink on top.
Printing a white underbase using low cure ink is another great option, but you must also print low cure plastisol on top of it so that the cure temperatures are the same.
Finally, one last parting thought on dye migration.
If you’re printing plastisol ink that is darker than the garment you’re printing on (example: black ink on white shirt, navy ink on grey hoodie) you can skip the special polyester inks and additives. While the dye from these garments may technically bleed into the ink, the darker ink prevents the dye migration from being visible.
Ok, one last parting thought :)
As with anything, the fail-safe way to know that your screenprinting process has gone smoothly is to TEST, TEST, TEST. Testing generally involves using one of the suggested methods above, printing your garments, waiting 72+ hours, and watching for dye migration. Though this takes extra time and is admittedly inconvenient, testing is the only way to definitively know that nothing has gone awry.
Good luck and happy printing!
rafael cardenas10/18/2020 07:51 pm
Can I apply gold ink color on the grey blocke base ink to avoid bleeding from the red polyester t-shirt?
ShirtSpace08/17/2022 10:55 pm
Hi, Rafael. This question was a little over our heads, so we reached out to our good friends over at Printera Screen Printing for some advice. Thankfully, they had a few suggestions. First, the answer here is dependent upon whether you are using a golden yellow ink or a metallic gold ink. Standard colors like golden yellow should always go on top of a base first when working on a polyester fabric. There are two ways you can successfully apply a base underneath the golden yellow color. The first option is using a white plastisol that is suitable for polyester. Since polyester plastisol inks are low cure, you have to be sure not to cure for too much time or at too high of a temperature or you will still have issues. The gray blocker base is what you would want to use on sublimated garments. Two layers are required for the gray blocker so you will print the blocker, flash, print the blocker again, flash, and then proceed with your other colors. You can print the golden yellow on the white ink or the gray blocker base to yield different results. Printing the golden yellow on white will give you a brighter, more vibrant color, while the gray could tone it down a bit. It just depends on what the shade of gray that the blocker you are working with happens to be. If the gray is light enough, any ink laid on top will probably be more true to color than when printed on top of white. As for the gold metallic ink, Now for metallic gold. According to Printera, in their experience, you want to print the metallic gold directly on the garment with no under base. Even on 100% poly and dye sublimated polyester, you shouldn't get any dye migration. It’s unclear why dye migration doesn’t occur, perhaps because the inks are formulated differently. An under base will tend to dull the metallic effects. Thank you for your question and best of luck printing!
Nina06/26/2020 03:00 pm
Hi, got a bit of a situation here. I’ve got some polyester/cotton sports leggings, printing a white logo over the top. I’m a bit familiar with dye migration, so I used water based super cover white ink instead of plastisol. I’ve done about 4 layers to make sure it’s a really solid white. Looked great till I cured it, it went grey in less than a minute. Tried dye block white, a bit better but loses some of the detail and still doesn’t look solid white. Any idea why water based turned grey? It’s never done that before. Even on 100% polyester garments.
ShirtSpace08/17/2022 11:03 pm
Hi, Nina We didn’t want to give poor advice so we reached out to some of the pros, our good friends over at Printera Screen Printing. They were able to offer a little advice to help with your conundrum: First of all, water based ink takes a lot longer to cure than plastisol. We're talking 90 seconds vs 20 seconds at the same temperature. That would probably be the first issue. A workaround for that is using a low cure additive for water based ink. This allows you to just dry the ink to the touch, rather than curing it for 90 seconds. The additive will cure the ink over a 48-hour period. Because of this, you'll want to avoid washing the printed garments right away. We've had great success with this method on 100% polyester. Dye sublimated will still have issues. Different brands of ink have different names for the additive, but Printera uses Warp Drive from Green Galaxy as the additive, and Comet White as the ink. “Dye Block White” could be referring to two things. The first would be a standard white plastisol with some bleed blocking. These inks work really well on 50% polyester and below. The other ink it would be is a poly white which is intended for 100% polyester fabrics. These inks are much thicker because of the dye blockers and they are hard to print. We’re talking using every ounce of strength in your body to push it through the screen hard lol. It's no joke, but it works. Even if the ink you are using is either one of these, cure time and temp is a huge factor. Usually you will never run into a poly white having dye migration on 100% polyester when cured properly. All garments are not created equal though, so your garment could possibly be over dyed too. In this case, if nothing mentioned above works then you'd want to bust out the blocker gray. This is a last resort since it's going to add another color to your print. Printing gray, flash, gray, flash, and then white should do the trick. Also, you wouldn't need to print the white more than once. It lays on the gray extremely opaque. We hope this helps with your complex printing problem. Thank you for reaching out to us, and best of luck printing!