Equestrian Decor White Linen 13" x 19" Feather Down Fill Hidden Zipper in the Back Information Tag Included: Jockeys wear the horse owner’s choice of silks, and their patterns and colors must be registered with the racing commission at the racetrack. There are over 20,000 silks registered worldwide through the jockey club. Bright and colorful silks help identify the horse during the race. Early on silks were made of silk, but today nylon and Lycra are the preferred fabrics because of their durability. These fabrics are also beneficial because they can be more form fitting adding an aerodynamic advantage.