Choke combats the phenomena that when printing the White ink Underbase onto a garment the garment will expand and swell.
This is the same for any type of garment printing including screen printing. The Choke setting slightly reduces the outside dimensions of the Underbase so that white ink does not appear outside the prints edges of the final color pass.
Under the Choke setting use the default value of 2 on a full size print, you will lower this if your image is small. If you see any white around the edges of your final print you will want to increase the choke value. If you are printing an image that is only white you will need to set the Choke to 0 to prevent parts from dropping out completely. Individual Color Adjustments By selecting a color from this drop down menu you are able to increase or decrease the amount of white ink Underbase that will print under that color. This will help you bump up or bring down certain colors in your final print. You can print multiple different colors using this setting.