The most common form of commercial T-shirt decoration is screen printing. In screen printing, a design is separated into individual colors. Plastisol or water-based inks are applied to the shirt through mesh screens partially coated with an emulsion that limits the areas where ink is deposited. In most commercial T-shirt printing, a limited number (typically one to four) of spot colors are used to print the design. Specialty inks trend in and out of fashion and include shimmer, puff, discharge, and chino-based inks. A metallic foil can be heat pressed and stamped onto any plastisol ink.