The purpose of pretreatment is to create a flat smooth surface on your garment so that ink can be applied to and adhere to the garment. Being made of a different composition than the color inks, white ink requires pretreatment to stay on the surface of the material.
The key to pretreatment is:
- Apply an evenly distributed amount of pre-treatment solution using an synthetic roller.
- Use the pretreatment and roller to flatten and smooth the surface of the garment.
- Roll in one direction preferably with the grain of the fabric to ensure no textile fuzz or imperfections in the weave of the fabric stick up.
Pretreatment Technique
Pretreatment is generally used in dark garment printing. The color of the material that you are printing on will impact the final appearance of the print because direct to garment printing use translucent inks. This means that in order to obtain the crispest colors possible on a dark garment, you need to create a white background on the garment.
All textiles have imperfections in their surface where ink can fall. In order to minimize this you need to create both a smooth surface to print your white background on and a surface with some additional adhesive qualities. The solution is to use pre-treatment in your dark garment printing process.
You should have a well ventilated room, a large flat surface for prep, and a container for your pretreatment solution. Lightly apply the pre-treatment solution to the shirt using the roller provided. Make sure that the print area becomes visibly damp, but not overly saturated. As long as total coverage is achieved, less pre-treatment is better for wash fastness and color vibrancy than too much pre-treatment.
- Make sure the heat press is set at the following settings:
- 330°F
- 45 seconds
- High Pressure (80psi) or the number 7, 8 or 9 displayed on the automatic heat presses. Reduce the pressure if the pretreat does not wash out.
- Heat set the blank shirt for 10 seconds; this will remove excess moisture and flatten the fibers while assisting with a smooth re-treatment application. Use a fresh sheet of silicone coated parchment or kraft paper.
- The shirt collar should be to the front; the fibers lay down from top to bottom (collar to bottom of shirt).
- Shake the pretreatment solution well to counteract settling. Make sure the cap is on tight before you begin.
- Pour enough pretreatment into a paint pan.
- Soak roller (do not over saturate).
- Apply the pretreatment by rolling in one direction from neck to bottom of shirt or desired coverage area (one direction only; do not roll forward and backward); apply a medium pressure to ensure that the pretreatment is getting into the fiber.
- Slightly overlap the roll. Dip the roller into pretreatment solution as needed.
- Hover the heat press over the shirt for 10 seconds.
- Cover the shirt with coated Kraft or parchment paper and close press.
- Remove shirt after 45 seconds or when the steam disappears
- Re-press for another 10 to 15 seconds if the shirt is still wet; this means you are applying too much pretreatment.
Excess pretreatment will come out after the shirt is washed.
Staining On Certain Color Shirts
Some color garments such as bright orange, lime green and hot pink have dyes that react with heat and pressure. This reaction can cause a bluish/reddish stain to be seen after the shirt is cured.
To prevent this, you need to follow the following steps:
- Do nor preheat garment.
- Spray the shirt down with distilled water.
- Apply pretreatment as described above.
- Hover for 10 seconds.
- Place parchment paper over garment and close heat press.
- Use the curing parameters settings for the pretreatment above, but extend the time to 60 seconds.