Index separation is a separation method that converts images using stochastic square dots of equal size instead of elliptical halftones.  Although an index separation isn’t right for every design, it does have many advantages for printers:

Index separation is a separation method that converts images using stochastic square dots of equal size instead of elliptical halftones.  Although an index separation isn’t right for every design, it does have many advantages for printers:

• No Moire!!!  The stochastic bitmap dots burn to mesh easily without the chance of a moire.
• No ink buildup.  Since the square dots sit side by side like a grid or puzzle, there’s no heavy ink build up.
• Prints look consistent printed on any colors, lights, darks, or brights.  Shirt color does not effect index seps the way they can with elliptical dots.
• Less variables on the press.  A good index separation eliminates many press variables you can encounter with other types of separations.  The 2 main things to watch on an index separation are registration and print order.  Print order will make a big difference in the look of the print and is a great advantage.  If a color is printing too prominently, just drop it down in the print sequence. 

Since the square dot pattern is already embedded in the color plates, output seps with elliptical dots at 55-65lpi and 45 degree angle for all inks.  This will convert any greyscale area to halftone on output.