We know that the Plastisol ink is based on Plasticizer, PVC, pigments and fillers. In order for liquid paste (Plastisol ink) to become a solid polymer film (Print), the PVC and Plasticizer mixture (Paste) has to be entirely fused together. The fusing of Plastisol ink for cotton and 50/50 occurs at 330-350 F. For polyester and Nylon inks, the fusion may take place somewhere between 225- 275 F, depending on the type of PVC and Plasticizer being used. These temperature ranges have to be maintained for one minute and twenty seconds in order to entirely cure the ink; otherwise the possibility of the ink washing out is enormous. The Flash unit allows the ink to form a skin on the top of the Plastisol ink; the inner side of the ink layer does not really cure at all. If you can hold 330-350 F under the Flash unit for one minute and twenty seconds, you may achieve the full curing of the ink. If the ink is not fully cured, two things may happen- 1: The ink may crack 2: The ink may wash out