Ghosting—the word that strikes terror and headaches in new and seasoned printers alike. Ghosting occurs when the screen-printing ink reacts to the dyes in the garment. This issue might not be noticeable right away, but before you know it you will find your image repeated on the backs and bottoms of your whole print job. Nothing is more embarrassing than sending a load of shirts home to a customer only to receive that dreaded phone call a day or two later.
This problem typically occurs on 50/50 colored garments printed with low-bleed white inks, but that doesn’t mean the problem couldn't occur in another printing situation. Shirt colors to look out for include light blue, violet, yellow, and green. Take extra caution with these when a customer places an order. Low-bleed inks are tempting to use to prevent dye migration with 50/50 garments, but they rarely stop dye migration from occurring.
Ghosting can happen due to some other factors:
- Moisture in the garments
- High humidity in your print shop
- Excessive PH and chemicals left in the garment by the manufacturer
- Not curing the ink for an appropriate amount of time
What are some solutions?
- Always make sure you have the right mesh, proper off-contact, and good screen tension for the job
- Have good, clean squeegees on hand
- If you are unsure, don’t stack your hot shirts
- Remember to test print, even when you feel it’s not necessary
To test a garment for ghosting, you can run through a simple test:
- Start by printing on a sample of the same material you will be printing the job with
- Take your test piece and place it on your heat press
- Mist with water to add moisture
- Cover your test piece with another sample of the same suspect material (sandwiching the print)
- Set your press to 250 degrees F and close the heat press and let it sit for approximately 30 minutes before evaluating
- Check the unprinted material for the ghost image
If the material is subject to discoloration, then you will see a ghost image on the unprinted material.