Frank Lloyd Wright Colored Saguaro Forms Design Doormat. Constructed in coir fiber pressed into a natural rubber base. Dimensions: 30 inches by 18 inches. The Saguaro Forms Doormat recreates one of Wright's most popular designs. Official Frank Lloyd Wright Collection item. The Frank Lloyd Wright Saguaro Forms Doormat recreates one of Wright's most popular designs. Saguaro Forms is one of a number of Liberty Magazine cover designs from 1926-27 that the editors thought to be too "radical" and never used. In 1973 there was a fire in the Arizona Biltmore. The graphic was selected from the Frank Lloyd Wright Archive to be rendered in stained glass in the reconstructed foyer. This doormat is constructed in coir fiber pressed into a rubber base. The proportions of this mat are 30 inches by 18 inches.