The acrylic fiber production process naturally yields continuous filament tow, and cutting to staple length is most efficiently done close to the end-use spinning operation. This allows spinners to optimize staple length for their specific yarn counts and machinery, making tow the standard commercial form for acrylic fiber trade.

The classification is determined at the time of importation based on the condition of the goods as entered. Acrylic tow imported in its uncut form classifies as tow regardless of the importer's intended downstream processing. However, if the tow is substantially transformed through domestic manufacturing, the resulting staple fiber would be considered a US-origin product for subsequent trade purposes.