Fiber Length

The length of cotton fiber with HVI text method at 2.5% span length measured in millimeters (mm). Fiber length is the average length of the longer half of the fibers (upperhalf mean length). Fiber length is measured by passing a “beard” of parallel fibers through an optical sensing point. The beard is formed when fibers from a sample of cotton are automatically grasped by a clamp, then combed and brushed into parallel orientation. Fiber length can be reported in 100ths and 32nds of an inch, however, international convention is to report in millimeters (mm). Fiber lengths are categorised into: Short (S) – Less than 25mm; Medium (M) – 25-30mm; Long (L) – 30-37mm; and Extra Long Staple (ELS) – Over 37mm.