One of the most common problems that occurs in screen printing is dye migration. It can cause nightmares for screen printers. If we had a nickel for every shirt that had a dye migration problem we would be wealthy people by now. We’ll talk about what dye migration is, how it occurs, and how you can prevent it.
What is Dye Migration?
Dye migration occurs when a polyester shirt is printed. The shirt is printed as normal. Then the ink must be cured at a temperature of 320 - 330 degrees. This is true of both plastisol ink and water based ink. Unfortunately when a polyester shirt reaches 280 degrees the color will release from the polyester fibers and bleed into the other colored inks on the shirt. This action can happen immediately, but sometimes it takes a few days for it to migrate.
So if you had a red polyester shirt with a white screen printed design the ink could migrate from the red colored fibers and travel onto the ink and it would turn pink. Not the intended outcome.
The process occurs because the heat turns the ink into a gas and that gas floats to different areas.
Preventing Dye Migration
This is a very common problem. Because it is a common problem people have developed solutions for the issue. They generally fall into five categories: low-cure inks, dye blockers, low-cure additives, printing an underbase, and choosing different garments.
This is the most common method of dye migration prevention. Manufacturers of plastisol ink have developed an ink that does not have to be cured at such a high temperature. Low-cure plastisol can be cured at 280. This has multiple advantages. The first obvious advantage is that the fibers don’t heat so high that they release their color. The second advantage is that you can run your dryers at a lower temperature. This will save money on electricity and it’s good for the environment. This option is a win-win.
Dye Blocking Polyester Inks
These inks are specially formulated for printing on polyester shirts. The ink merely blocks the other shirt dye from mixing with it. These inks are typically more expensive than regular plastisol inks.
This is a substance that you add to regular plastisol ink. The ink then acts the same as a low-cure ink. Low-cure additives are sold wherever you purchase plastisol.
Print an Underbase
An underbase can be printed and then cured. This is a common practice on dark color shirts. The underbase can be made with low-cure or dye blocking ink, then the top layer can be laid on. The benefits of this method are that you won’t have to deal with dye migration and the colors will appear brighter.
Choose Apparel That Prevents Dye Migration
It is possible to find blank garments that do not have dye migration issues and are very similar to polyester garments. They hold their color longer. Steering a customer towards choosing one of these options may be a better option for the customer. It should be noted that these shirts may come with a higher price tag.
Perform a Dye Migration Test
It can’t be said enough...test, test, test. Did we mention that you should test. It is much better to discover that your garment has a dye migration issue well before it is printed for the customer. Test the printing and put it in the washing machine. See if it changes over a few washes. Do not wait until a large batch of shirts has been printed. You could end up with an unhappy customer and lost revenue due to a batch of shirts having to be reprinted.
The Final Word on Dye Migration
This is a common problem. Many screen printers have been through this and many more will go through it again. It’s almost a right of passage. Just know that you have options when it comes to dealing with the situation. Test your garments and see what works. Then you will avoid the dreaded dye migration dilemma.