There is considerable interest among textile manufacturers regarding the shorter fibers of a cotton’s length distribution. The relationship between a cotton’s short fiber content (SFC) and processing waste during opening, carding and spinning is an obvious one. The relationships between SFC and spinning efficiency, yarn evenness, and yarn strength are more difficult to establish. Apparently, mature strong cottons maintain their original length distributions better than immature weak cottons. For a given high volume instrument (HVI) the upper half mean length (UHM) and the length uniformity index (UI) tends to vary directly with fiber bundle strength. As the bundle strength decreases, so does the UI.