Ghosting can be an absolute business killer in screen printing. Sounds a little extreme, right? Well, imagine completing an order of 500 green garment-dyed shirts printed with a low-bleed white base and the customer comes to pick them up and leaves your shop satisfied only for you to get a call an hour later asking why you printed something on the back of their shirts and for their money back. Believe it or not this happens, and it’s called ghosting. It’s important to understand how and when ghosting happens. It occurs when low-bleed white inks react with certain dyes in certain shirts. It mostly happens on light blues, violet, yellows and greens but not nearly as much on darker colors like navy or black. The reaction that causes ghosting occurs especially in high humidity and heat. A high PH level remaining in the garments from the manufacturer or high humidity in your shop, which will cause your garments to retain moisture, are two of the biggest factors that cause ghosting. Coincidentally, ghosting usually happens when you’re trying to prevent other problems from happening.
It’s understandable that you’d want to use low-bleed inks in this case; however, ghosting almost always occurs when using said inks. Unfortunately, low-bleed white inks will never stop the dye migration or “bleeding” that occurs with garment dyed shirts. Some other factors to consider that will cause ghosting include using a dryer with a short heat chamber which equates to less time for moisture to evaporate and less time for the ink to fully cure. Using a dryer with a short take off results in your shirts being nearly on fire when they come off the belt. Therefore, if you’re printing at a faster pace than normal, most likely your shirts aren’t getting fully cured but are piping hot when stacked together which results in an “insulating” effect on the shirts that prevents moisture from escaping.
Now that we better understand what causes ghosting and how it occurs, let’s talk about how you can prevent it in the future. Like anything in screen printing, the key to success is in the preparation. The right mesh count, a good and level press, good squeegees, the proper off-contact and healthy screen tension should be set up in the beginning to decrease the likelihood of problems. Next, use low-bleed ink only when necessary- use cotton whites for 100 percent cotton and low-bleed only for 50/50 poly blends. The low-bleed EZ Print white ink from Union Inks Maxopake series is a great low-bleed to use for both light and dark, cotton or 50/50 garments. You can also run your shirts through your dryer before printing to remove any moisture that may have been left behind from the manufacturer. Be careful who supplies your shirts and make sure they’re a high-quality manufacturer, especially when dealing with light-colored garments. Lastly, make sure you cure the ink properly, don’t over flash or over heat your shirts in the dryer. If you’re not sure your garments are susceptible to ghosting, you can run a test on them to be sure. Simply print one shirt and cure, then cover the print with a piece of the same fabric (or a spare shirt if you have one) and set in a heat press set to 200 degrees and 5 PSI. Close the press and leave for approximately four hours after which you’ll do a visual check, if you see a “ghost” image of your print on the piece that was covering the printed area, then you’ll know for sure. we hope you found some helpful tips in this article on how to handle ghosting and prevent it in the future.