Simulated Process Color Great for dark shirts that need a photorealistic image. Works on light shirts too. Requires good separations, screen making and printing technique. Can print very smooth gradations and hold excellent detail. The most popular method used by award winning printers.
Prints are bright because all purpose inks are used.
Index Color Works on light and dark shirts. Very easy to print because all the dots are the same size and you are printing square dots next to square dots rather than halftone dots on top of halftone dots. Separations are easy to do in Adobe Photoshop and screen making and printing can be forgiving. Very production friendly and easy to print. Works well for spot color also.