This 1 Gallon bottle of Pretreatment is a non-toxic spray that needs to be applied to the garment before printing white or color ink on dark garments. All Direct to Garment Printers that print white ink on dark garments require some sort of garment pretreatment. Usually the pretreatment is a spray and you spray the shirt and hit it with a heat press. This lays down all the fibers, giving you a nice, smooth garment to print. The pretreatment also helps ink to adhere to the garment, giving you a more vibrant final print and little or no fibrillation (small fibers sticking up out of the ink) PRETREATMENT IS A SERIOUS PRODUCT AND SHOULD PROPER MATERIALS SUCH AS GOGGLES AND MASKS SHOULD BE WORN AT ALL TIMES WHEN APPLYING. IT IS NON TOXIC BUT CAN BE TOXIC TO THE BODY IF INHALED. REMEMBER THAT PRETREATMENT IS GLUE, YOU BREATHE IN GLUE AND YOUR BODY WILL REACT TO THIS NEGATIVELY OVER TIME.