The 'Long' is a rectangular fabric made of cotton and hemp, with a black hue on a red background. Beginning from 2000 years ago, Iranians wore two kinds of aprons: one made of leather used specifically by laborers and soldiers, and the other made of fabric (mostly hemp, though occasionally from soft wool) for officials and laymen. Throughout the ages, the hemp apron evolved into a square pattern that served to distinguish Iranians from the others. Over the course of history, Iranian settlements in the fertile regions of Qazvin succeeded in discovering the secret to dying these fabrics. From then on, Iranian loincloths, much like their traditional carpets, took on a special red hue that is permanent in nature. The red-colored hues of Iranian 'Longs' are derived from a wild flower that is found in the central and southern regions of the country. In the spring, young ladies would collect these flowers and boil them in large cauldrons. The red hue that would emerge was a fiery one that remains permanently if washed in special spring waters. From the 19th century onward, red-colored Longs that distinguished Persians from other Muslims were used exclusively in baths located in gymnasiums (zoor-khaneh) dedicated to traditional Iranian martial arts. During traditional wrestling matches between two mighty opponents, the referee would stop the match by throwing a long in the middle of the arena before separating the opponents and declaring the winner.