If you have been in the industry long enough, you have probably heard the term dye migration. You have probably also learned that it is one of the biggest pain in the necks for screen printers, but there are a few simple tricks that will keep you from a headache later on. Before we get to the tips, it is important to understand what dye migration is and how it occurs. Understanding that will equip you with the knowledge to prevent it from happening in your future prints.
Note the washed-out color of the shirt on the right.
That is cause by dye migration.
Dye migration is caused by curing the ink too hot. This unwanted reaction occurs when the heat turns the shirt’s dye into a gas. That gas seeps into the plastisol ink causing an adverse reaction. What is even worse is that it can take up to days before you realize you have been subject to dye migration. This could mean that you already sent out product to your paying customer, they wash the shirts, the print comes out diminished and your shop gets a bad review. That is the last thing we want to happen. The surest way is doing a test run/wash to see if the colors “run” or bleed. If they do – that’s dye migration. But before you panic and decide to never print a single shirt again, there are a few tips below that can help!
The Truth Behind Inks
Firstly, there is no such thing as “no bleed” inks. Every ink bleeds to some degree, but there are a couple of options out there that are specially formulated to be as “bleed resistant” as possible. When using low-bleed inks, you will likely have to print a white under base and print your colors on top. While low-bleed inks work more for polyester materials, printing the white under base ensures that your colors will appear just as vibrant when you first print them because white has a good dye migration resistance. A second option is to print with silicone ink. The down side to using silicone is that you will get a thicker print which may not be what you need for the specific print job you are working on.
Try a Blocker
A third option for you is to try a blocker as an under base. They act as a shield to protect the plastisol print from the shirt dye. An under base may just be your shops best friend in fighting dye migration. There are “blockers” that are specially designed for use as a dye migration-blocking under base on polyester and performance fabrics.
Cure at a Lower Temperature
One of the most important factors to consider is curing temperature. Polyester starts to release its dye around 280F, but most plastisol inks don’t start curing until 320F. Then what happens is the dye of the shirt seeps into the plastisol so when you go to wash it you will find the print is less than perfect. Another factor is the color of the shirt. Dye migration is most common on dark or bright colored garments like red, blue and black.