Screenprint is the most widely-used method of printing on garments. First, the image is cleaned up, colour-separated, and printed onto acetate film (one for each print colour.) This acetate is applied to an emulsion-treated silk screen, such that the image masks the emulsion when the screen is exposed to a light source. The light “cures” the unmasked emulsion, which becomes opaque; the masked (and therefore un-cured) emulsion which remains is washed away, and the result is a screen with the image represented by open mesh where the acetate had been. The screen is placed on a garment, and ink drawn across and through the screen; as ink can only pass through the open mesh, only the image is transferred to the garment. Each colour is flash-cured before the next colour is applied on top, building up to the composite colour image; the garment is then passed through a tunnel-dryer to cure the ink at a very high (and very specific) temperature.