SK Direct-to-Garment Pretreatment
Any time white ink is used in the direct-to-garment printing process, it is critical to properly apply a quality pretreatment prior to printing. Proper application of this pretreatment is critical to obtaining bright, opaque whites and a washable garment. Improper application may result in inconsistent white opaqueness, dull colors or cracking and pealing ink after wash. If you experience any of these issues, your first question should be “was the garment pretreated properly.” Below you will find our, ‘real world lab tested’ process for properly applying our SK Direct-to-Garment pretreatment liquid. We encourage you to watch the video and review these instructions before printing dark garments.
STEP 1: Fill Sprayer
Depending on your set up and needs, you can use a pretreatment machine, spray gun or even a simple spray bottle when doing single garments in a pinch. The first step is to fill your sprayer with the needed amount of liquid. Please note: SK Direct-to-Garment Pretreatment Liquid is already mixed to the ideal concentration, so there is no need to dilute with water. Diluting the mixture may result in print failure and reduced washability.
STEP 2: Spray Garment
Spray SK Pretreatment on garment. Your target amount of liquid is about 20-30 grams (0.88-1.05 oz.) per 15” x 18” area. We encourage you to watch the above video to see what the correct amount of liquid looks like on a garment. If you are using a pretreat machine, you can dial this in with your controls. Or if you are using a spray gun, then you can control the amount by either slowing down your passes or repeating passes with the spray gun.
STEP 3: Sqeegee Garment
Use a plastic squeegee in a single direction to flatten the fibers and evenly spread the pretreatment into the garment. You do not need to apply a significant amount of pressure.
STEP 4: Dry Garment
Next you need to remove the moisture from the garment. With SK Pretreatment, you can use either a heat press or forced air conveyer dryer.
Heat Press Method – Use a sheet of parchment paper or teflon sheet to protect the garment from the heating element and press the garment at 335°F (170°C) for 45-60 seconds with Medium-to-Light Pressure. You will notice some steam discharge. After the first press, check that the parchment paper or teflon does not stick to the garment. If it is still sticking, peel the sheet off, place it back on the garment and press again for another 10-15 seconds. Repeat as necessary until the paper is no longer sticking to the garment and the garment is dry to the touch.
Forced Air Conveyer Drying Method – If you have a conveyer dryer, you can simply run your pretreated garment through your dryer for 180 seconds at 335°F (170°C). If the garment is not fully dry after 180 seconds, increase the time in the dryer or slow down the conveyer.
Printing Pretreated Garments Instructions
Step 1: Pre-Press Garment
Before you print a garment that has been pretreated, it is important to flatten the fibers using the heat press. If you are pretreating your garment and finishing with the heat press, you can move directly to print as long as you do not touch the printing surface. If some time has passed after pretreating and you are unsure if there is some fibrillation in the fibers, it is always a good idea to do a quick 10 second pre-press. This will also serve the purpose to remove any excess moisture in the garment that may have been absorbed from the environment or after the pretreat process.
Step 2: Print Graphic
Print your garment as normal.
Step 3: Hover Heat Press
If the ink is still very wet, it may be helpful to hover the heat press over the ink prior to applying pressure to make sure ink is slightly dry to avoid bleeding or migration of ink. Do not apply paper or teflon during this step.
Step 4: Cure Ink
Now apply the heat press paper or teflon and fully apply pressure on the heat press set to 335°F (170°C) for 45-60 seconds with Medium-to-Light Pressure.