Misprint Monday – Another Kind of Ghost
I was asked to look at some shirts today that supposedly had “ghosting” issues. Ghosting we have covered before (see a prior ink kitchen.com article), it basically is a bleaching process when certain inks give off a gas when they are hot and stacked and a lighter “ghost” image appears on the shirt placed on top of the ink. It also can happen from the front to the back of one shirt in the oven as well or around a print on one shirt.
I received the shirts today and determined that they probably did not have ghosting, but rather a different problem. The issue was subtle, so subtle I could not get a good photo of it. Basically there was an image from one shirt showing up on another shirt. It was darker not lighter though and that’s why I think it was not ghosting. I think plasticizer was leaking into the other shirt. Plastisol ink is made from plasticizer and resin which fuse together at a temperature that is usually around 320 degrees F. If you put wet ink on a shirt and don’t cure it, the plasticizer is liquid and will wick into the surrounding fabric, much like you would see quickly if you put wet uncured plastisol ink on a piece of paper.
Probably some combination of the following occurred:
- poorly mixed ink
- insufficient curing of the ink
- possible overloading percentage-wise of plasticizer. Plasticizer is generally added to get more penetration into the fabric or a softer hand. If put in too high of a concentration the ink will not fully cure (plasticizer is usually called “non-curable reducer” in our industry.)
To avoid this make sure your percentage of non-curable reducer does not surpass your manufacturer’s recommendations and make sure you cure your ink fully.