A common issue you’ll run into at your screen printing shop is dye migration. Learn some tips for keeping your prints vibrant!
Dye Migration Defined
Dye migration is actually the second step in a chemical process that can affect your prints – a process that begins with dye sublimation and ends with bleed.
- Dye sublimation is a chemical process where dyes in the fabric turn from solid to gas during ink curing.
- Dye migration is when the dye in gas form seeps into the layer of ink.
- Bleed is the resulting discoloration from the migrated dye.
Dye migration isn’t 100% unavoidable. There’s no way to totally prevent bleeding, but there are steps you can take to control it. Some shirts are more prone to dye migration than others, especially red fabrics. You’ll probably run into this issue most often when printing plastisol inks on synthetic materials like polyester. Athletic apparel can be particularly problematic, being largely synthetic. (Check out this post for more help overcoming the challenges of sportswear)
Steps You Can Take to Avoid Dye Migration
One way to avoid dye migration is to keep from overcuring your garments. By carefully keeping track of your conveyor dryer and flash cure temperature, you can limit the plastisol ink’s ability to sublimate and reduce bleeding. Make sure you monitor your dryer and flash cure temperature for consistent results – don’t overheat your garments. A dryer with accurate adjustable time and temperature settings will be a big help towards curing your garments just right. Let the ink reach the manufacturer’s recommeded cure temperature without exceeding 330°F fabric temperature. You can use inks specially designed to cure at lower temperatures than standard plastisol for added protection against dye migration.
Adjust your flash cure time and temperature to
make sure you aren’t overcuring your garments.
Another step you can take to avoid dye migration is to use the highest quality shirts you can. Poor quality shirts may contain substandard dyes that bleed more easily than higher quality products. You also have to be careful of re-dyed shirts, which have a greater tendency to bleed regardless of the fabric content. Because shirt factors are often largely beyond your control, you should use the highest quality ink you can when printing white ink on dark garments.
Testing Helps Catch Issues
The last thing you want is to send your customer a fresh batch of shirts, only for them to be returned because the print ended up discolored. The best way to be sure your prints will stay sharp and vibrant is to test thoroughly. A crock test is an easy way to get an idea of how susceptible your garment is to bleeding. Take a piece of dry white cotton fabric and rub the garment with it. Then repeat with wet cotton fabric. It’s normal if a little bit of color comes off, but if a lot does, you might have bleed issues with your prints. If that’s the case, you should consider using different shirts if possible.
It’s a good idea to print samples of your orders as far in advance as possible and monitor them for bleeding over time. It can take days or even weeks for the results of dye migration to show up in your products. If you keep an eye on your sample prints for awhile, you may be able to catch delayed problems before you send the order to the customer.
While dye migration isn’t totally preventable, by following the advice above you can reduce the chances of it affecting your print quality. With the right supplies and equipment and some careful attention, you can provide your customers with long-lasting, vibrant prints that will keep them coming back for more.
Dye migration certainly isn’t the only problem you’ll have to combat as a screen printer! Want some more tips on how to make life easier for yourself? Check out our blog post: Screen Printing Quality Control: Stop Problems Before They Start