What is discharge printing?
Updated: Dec 31, 2022
You may have noticed that many of our designs list Discharge Ink in the description but what is discharge ink and why should you care?
I started this business because I was not happy with the product print shops where putting out on shirts I ordered from them.
One of the most common inks used in screen printing is Plastisol Ink. This ink has many advantages for the shops that use them. This ink is essentially liquid plastic and It doesn’t evaporate. The ink can can be left on the screen overnight and continue printing the next morning with no issues. It is easy to move at room temperature, and cures painlessly making large production runs fairly easily when compared to other printing options. Plastisol also has a high opacity this means the ink covers the shirt color well and is more forgiving with mistakes. If needed the error can often be corrected with another pass.
When ordering shirts from these providers in the past the print shop used Plastisol Ink and I absolutely hated the look and feel of the garments. The ink sits on top of the fabric and can be felt when running your hand over the design. In addition to the rough feel of the ink the design would crack and break after a few washes.
Water based inks are another common type of application and I use them often based on the design. Water based inks sit in the fabric and offer a softer "hand". Hand refers to how the design feels on the shirt, the lighter the hand the less noticeable the ink will be felt on the garment.
Water based inks also provide a solid print but often not as bright as plastisol ink, because the ink sits in the fabric a solid white base layer is usually laid down first so that the colors placed on top will pop out. The more layers that are added increase the hand. In some cases, the under base is not used but this decreases the opacity of the ink.
While water-based inks offer a more comfortable feel over plastisol there are drawbacks to using the ink in production of large runs which is why shops often avoid using them. The water these types of ink begin to evaporate once it’s exposed to air. If the ink sits on a screen for an extended period of time it will dry out.
Curing water-based inks is a little trickier. Curing the ink is the process in which the ink is dried on the garment. As discussed earlier there is water in the ink and the water must completely be evaporated. Once all the water has been removed, the remaining ink layer (the resins in the ink) need to reach the recommended cure temperature and hold at that temp to cure properly.
While the benefits of water-based inks are many, several shops avoid using them due to the time-consuming procedures.
It wasn't until a visit to Las Vegas in 2018 that I came across a shirt that really caught my eye. The design was super cool and when I took it off the rack, I was amazed at how soft the shirt was and that I couldn't feel the design. My mind was blown and when I returned to Illinois I reached out to several shops in the area to see how this was shirt was printed. To my surprise my local shops didn't know what type of ink was used or told me it was most likely discharge ink and they didn't offer that application as an option.
I later came to find out that discharge ink uses a very labor-intensive process to get the desired result. Discharge ink does not sit on top of the shirt or soak in the fibers but rather removes the original dye from the shirt, almost like bleaching the design into the shirt without the damaging properties of chemical to the garment.
Because the ink removes the dye the design has zero hand and won't crack or brake over time.
There are many draw backs to using discharge ink that discourages ink shops from offering this service.
For consistent results discharge ink works best on 100% cotton shirts that are black or a dark color. While the ink can be used on tri-blends, CVC, and other fabrics the results will vary from fabric and even from shirt to shirt.
Discharge ink is great for a vintage look and feel however it can't compete with bright colors compared to plastisol or water-based inks.
The major deterrent for big shops is that the activator added to discharge ink is a compound molecule called Zinc Formaldehyde Sulfoxylate. The discharge process begins from high heat, either during flashing or curing, breaking apart the activator molecule. Once the activator is in its separate components, the formaldehyde attaches to the fabric dye and breaks the dye molecule. It's this process which removes the color from the garment being printing on. The chemical reaction produces a toxic smell that requires a well-ventilated room and the use of a respirator mask.
While the process is labor intensive for big shops doing large runs it offers the perfect solution for Outlawed Ink and our designs offering a unique look and feel to our garments.
Before the ink is applied the correct garment needs to be selected. Discharge ink works best on 100% ring spun cotton that has not been "over dyed". Over dye is when a company will take a shirt that is one color that may not be selling well and re-dye into a different color. While this does bring down the cost of blank garment in yields inconsistent results from shirt to shirt. When using discharge inks, we only use top brands that are dyed once.
What is really cool is watching the discharge process in action. The ink is applied to the garment using the screen-printing method. Once on the shirt the ink is lacking opacity and depending on the color being used the design may just appear to be wet. The magic happens when the garment is placed under a heat source and the activator kicks in. Right before your eyes the design comes to life as the discharge agent evaporates the original dye from the shirt.
There are a few ways we apply the ink at Outlawed Ink, if the design calls for just white, we may use only the base ink with the activator. This method exposes the natural color of the white cotton providing the softest hand possible. When color is needed, we custom mix pigments in with the base layer and as the dye is removed from the shirt the color goes into the fibers.
So why is discharge ink important? Well, if you are the type of rebel that is looking for top quality apparel, with the softest hand, with the most badass designs on the most comfortable shirt you will truly appreciate Outlawed Ink Apparel.
If look, feel, and imagery doesn't matter to you then 1) you found this website by accident, and 2) Walmart will have the value you seek.