THE CLOTH OF CHAMPIONS
Simonis cloth looks, feels and wears differently than any other billiard cloth. True to the spirit of enhancing the game, Simonis offered the first worsted cloth for billiards. Why worsted cloth? Worsted construction means that there are no short fibers that can release from the cloth to form "pills" or fuzz-balls that have to be removed from the playfield in order to allow the ball to roll straight. Simonis cloth is incredibly smooth without felt-like fuzziness. Simonis' construction does not allow the cloth to wear like nappy woolen cloth which eventually develops tracks or grooves in the cloth, all the while shedding short fibers that constantly need to be removed. With Simonis, ball spin is consistent, and the roll stays straight and true on every shot.

The following is from the Simonis web site. When installing Simonis cloth, be sure to put the SMOOTH SIDE UP. The smooth side also has printing on the edge with the grade, i.e. SIMONIS 860. This is the playing surface of the cloth. (The back of the cloth is not sheared as fine and is slightly fuzzy)
Simonis is NOT a "felt", it is carefully and precisely woven fabric designed specifically to enhance your game by allowing the balls to roll straight and true while still maintaining consistent speed and spin.
Learn more... about Installing Simonis