Pretreating is the process of preparing a garment for printing with white ink that utilizes pretreatment to prevent the absorption of it into the fibers.

The pretreatment fluid creates a chemical barrier on the garment that causes a chemical reaction when the white ink touches it that gels the bottom of the ink and allows it to sit on the top of the fibers to create a good underbase to print the CMYK inks on.

Users typically apply the pretreat fluid to a garment using an automatic pretreater get uniform coverage and the proper amount.

The pretreated shirt is then cured on a heat press for 35 seconds at 356 degrees F with heavy pressure prior to being printed.

Additionally, some users will pretreat a garment that is being printed only with CMYK inks when printing on polyester, blends or cotton garments as it makes the colors pop more.