DX is the basic Innova plastic.
"Our DX Line is produced with our Deluxe plastic. The DX Line offers the widest selection of models and weights. These discs are affordably priced and provide an excellent grip in a variety of weather situations. DX discs wear in with usage and over time will eventually take on new and varied flight characteristics."
Champion is a see-through tough plastic that lasts longer than DX.
"Our Champion line is produced with a hi-tech plastic that provides outstanding performance and durability. Champion discs are distinguished by a beautiful clear appearance. Designed for professional players, Champion line discs are usually a little firmer and more stable than the same model in other plastics. Whether used in heavily wooded situations, or on extremely rugged courses, our Champion line plastic will continue to perform predictably and avoid damage better than any other plastic."
Gstar is a premium plastic, feels softer than Star.
"GStar is a blend of Star that adds flexibility and even more grip. GStar is opaque like Star, but features a pearlescent sheen. Their allure is only surpassed by their beautiful flight. GStar discs have a smooth, gradual transition in flight and the same durability as our Star Line."
KC Pro is more stiff than DX.
"Our KC Pro plastic was developed for the demanding needs of 12 time World Disc Golf Champion Ken Climo. This plastic is the favorite putter and midrange plastic of many pros who would also like to be world champions."
R-Pro is a softer blend than DX.
"Our R-Pro line is softer than most Pro blends. R-Pro discs have the best all-condition grip and an improved feel. R-Pro has great flexibility which makes it the best choice for putt & approach in cold/wet weather. The R-Pro Boss currently holds the Distance World Record at 1108 feet (338 M)."
Star is a tough, opaque premium plastic.
"Our Star line is created with a special blend of grippy, resilient polymers. Star plastic offers the same outstanding durability of our regular Champion plastic, plus improved grip like our Pro plastic. Star discs have the same flight characteristics as Champion discs, but are slightly less firm. High performance, longevity, and superior grip make Innova Star line discs a great choice for your game."
All quotes are from Innova Champion Discs.