Filament tow consists of a large number of parallel, essentially untwisted continuous filaments gathered into a rope-like bundle, intended to be cut into staple fiber. It is classified separately from both staple fiber (which is already cut) and continuous filament yarn (which has twist and is ready for weaving or knitting). The absence of twist and the tow's intended downstream cutting process are the key classification criteria.

Acetate filament tow is the dominant form traded internationally and is used almost exclusively as the filter material in cigarette manufacturing. This concentrated end-use means that trade volumes are closely correlated with tobacco industry production levels and regulatory trends affecting cigarette consumption, making demand forecasting for this commodity quite different from general textile fiber markets.