As we discussed, water-based screenprinting ink is typically a better option when printing on fashion blanks because the hand (feel) of the ink is so much softer. If done right, you should not be able to feel the ink on the garment once it’s been washed.
Water-based ink by itself does not have a high opacity (coverage) due to the viscosity (thickness) of the ink. It is truly liquid form with low density making the colors very dull when printed directly on on dark garments.
In order to use this ink on dark shirts, you need to print a white base or add a discharge agent to the ink. The discharge agent creates a chemical reaction. Once heated to the proper temperature, it actually pulls the dye from the fabric and integrates the new ink pigment. This allows for nice bright coverage.
Unfortunately, not all shirt dyes have the same chemical compound. This can make for inconsistent color matching. We recommend several fashion brands that we found work the best for this process.Bella Canvas
Next Level Apparel
The other downside to printing water based ink is the limitations for sourcing the right fabric. If printing on a dark garment, the majority of the fabric must be cotton.
For best results and bright colors, 100% cotton is required. Water-based ink can be used to print on tri-blends or 50/50 blends, but the colors will be muted. The dye holds to the cotton fibers only. When you have other foreign materials in the fabric such as polyester, rayon, or modal, the reaction process is limited, causing the print to look faded or dull. So a 50/50 tee would only show roughly 50% opacity since the Polyester won’t hold water based screen printing ink.
One option to mitigate this problem is called hybrid printing. This is the process of using a discharge base, which pulls the dye out creating a soft underlay, and then printing plastisol or fashion based ink on top. This will help reduce the hand (feel) of the ink while still keeping the colors bright.
The other downside to this ink from a production standpoint is the shelf life. Unlike plastisol, water-based ink will dry out and go bad. Once you add discharge agent to the ink, you only have 48 hours to use it again or it expires. This can be offset by not adding the agent to the ink until ready to print, but it can be difficult to judge how much ink to mix for each job.
This process causes more waste. With this considered, although it is a more sustainable option, there is excess waste for this process which can offset the “green” or eco friendly values of the product. That being said, water based printing is still the most eco friendly screen printing ink type available.
Natural ingredients (for light garments)
Allows skin to breathe through print (less sweaty)
Less color accuracy