A gradient image refers to an image that has tones or shades in it. It is not a spot color or one block of color, but rather it has depth. Gradient imaging can be accomplished in screen printing by using half tones to emulate the gradient. In order to output half tones you need a half tone compatible printer, also known as a post script printer. The easiest way to print half tones is to combine a third party RIP (Raster Image Processor) Software with an inkjet Epson printer. The RIP converts the printer into a post script printer, which can print optimal positive films with half tones and opaque black ink.