Very coarse particles, like kosher salt. Grind this way for a French Press.
French Press: The best way to control the time and temperature of the extraction is to use a French press. The French press offers unparalleled flavor due to perfect extraction time and delivery of the volatile oils that are often trapped in filters. A French press is also the least expensive brewer available. Unfortunately, the French press is not quite as convenient as a drip maker due to preparation time and cleaning time. The French press also loses heat faster than some other methods, but extraction at slightly varying temperatures will promote a more dynamic and complex cup of coffee.
Coarse grind is also used for a cold brewing method such as with Toddy filters to make iced coffee.

Grind Image

Coarse Image

Recommended Brew Method

French Press