*To the right is an example of an instance when dye migration occurred. The color of the design was white, but dye migration caused the red tint.
Polyester is one of the most challenging fabrics to print on. It’s advisable to stay away from 50/50 blends in a lot of cases.
Being in the decorated apparel business, we are often asked whether or not we can print on certain types of fabric. In almost all cases, the answer is, “Yes"; however, not all fabrics get along with ink so well - which alters our response to “Yes".
Why is it a problem?
The reason polyester can be a struggle to print on is because of a reaction known as dye migration. Dye migration is basically just as it sounds; small dye particles moving from one place (fabric) to another (ink). This causes an unwanted change or tint in ink color.
When does the problem occur?
Dye migration occurs during what is known as “curing”. The chemical process is a little more complex, but curing is the drying of screen printed inks. During the curing process, the garment is placed on a conveyer belt, which runs under a radiant heat source set at 320 degrees. Once the ink is exposed to the 320-degree heat, it is “cured”. However, the heat is the cause of the migration.
Once polyester is exposed to heat around 300 degrees, dye migration begins to occur. Since the heat is necessary for the curing process, the screen print industry is always looking for ways to combat this undesirable result. To date, there is no solution guaranteed to work in all cases.
How we deal with the problem?
Unfortunately, when printing on polyester, you will almost always see a slight change in color. To achieve the best quality possible, we use two different approaches:
- One-stoke White – This is a specially formulated white ink that can be used as an underbase to help block dye migration. Once this layer of ink is laid, any color plastisol ink can be layered over it to give the garment the colors that you are looking for.
- Gray Underbase – This is thicker ink that dries at a lower temperature, which helps to limit dye migration. Because it is thicker ink, we tend to use it only on Dri-FIT Performance Polyester shirts.