Well folks, here we are for another rousing edition of automatic printing tips and tricks. The topic this time: water based ink. I’ll be honest, it hasn’t always been my favorite medium. My very first print way back in 1986 was done with water based ink, and turned out to be a huge failure. Looking back years later, I can see that I set myself up for failure.
Today’s water based inks are the bomb. They have longer open times, provide a softer feel and are generally pretty easy to print, providing you follow some simple rules. So let me pass on some of the lessons I learned since that first print, to help you avoid falling into the same traps.
Some differences to note between water based and plastisol ink:
The first thing you will note is the consistency of the ink itself. It’s similar to yogurt, unlike plastisol, which is viscous and will hold its shape until it is heated. A good analogy comparing water based ink to plastisol is to think of water based like a stain and plastisol like a paint. The water in the water based ink is the delivery agent, and when it evaporates, the color remains embedded into the garment leaving a very soft feeling. Plastisol sits on top of the garment like a paint, leaving a rubbery feeling and very little breathability.
Tips for printing water based ink on an automatic:
Handling: Stir ink prior to use and re-cap the container every time. Open air will dry out water based ink containers. Store in a mild temperature area. Check your ink before returning any extras to the original container, often times the ink can color shift or have partial dried ink embedded in the used portion. Discard the remainder!
Curing: A combination of forced air and heat make up the magic behind curing water based inks. Having the proper tools such as a thermo probe flash unit or a gas dryer are ideal, though we do offer electric conveyors which provide adequate curing at a lower volume.
Screen Prep: You will need special water resistant emulsion in order for the screen to survive the print process. Water will break down standard emulsion pretty quickly so take extra steps to ensure your coated screens are completely dry and no moisture remains in the emulsion. Then, crank on the dehumidifier, and let the screens sit for 24 hours to make sure that the moisture has fully evaporated from the screens. Some emulsion types I recommend are Baselayr Complete and Baselayr Long Lasting Emulsion.
Taping: Use a good plastic tape that will keep the ink inside the screen. Remember, water based ink will find its way into places it shouldn’t be. Use a good block out tape like R-Tape or Ryonet® Green Screen Tape. For added measure, I recommend taping underneath the screen to prevent additional breakdown caused from the squeegee and flood bar.
Ink Loading/Pre-Flood: Water based ink can dry quicker than you would expect. I recommend loading a good amount of ink into the screen. As the boards get warm, the ink will start to dry on the outer edges and move inward. Keep an ink card on the side of the screen to move the ink to the center to prevent this. It is also common practice to keep a spray bottle nearby to lightly mist the ink. The ROQ also has a print feature (normal mode) that will allow the floods bars to pull forward and keep the screen flooded, this will greatly reduce ink from drying during print cycles. Remember to raise the floods up slightly higher to prevent the ink from setting upto quickly. In the past, we have kept our water based ink alive in our screens overnight by slipping a plastic bag over the top of the screen and taping it down. Pay special attention to your environment as well. Shops located in drier climates will have more issues with keeping the ink from drying, and wet zones like the NW will have a better chance of getting more mileage due to moisture in the air.
Pressure: Typically we use less pressure for plastisol printing, but water based ink needs to be driven into the shirt. Up the pressure and slow the print stroke down. Try using the Euro mode “SQUEEGEE TO SQUEEGEE”, this will help you load up the image with ink and eliminate the winged floods from possible premature wear on the screens. European printers use this technique to put less wear and tear on the screen. Try it! It’s a winning combination.
Water based ink is still one of the oldest print mediums, and it has only improved with age. Look at the advantages: soft feeling prints, breathability, non-cracking or easily washing out, reduced chemicals to clean screens and tools. Water based ink is the wave of the future.
Just dipping your toes into the realm of water based printing? Perhaps you’re looking for more information on its pros and cons? Unique benefits and limitations? Requirements and rewards?….Or maybe simply, how to print with water based ink?