What is a feature of filament yarns?

Filament yarns are characterized by their construction, which involves the use of long continuous strands of fiber. Unlike staple yarns, which are made from shorter lengths of fiber twisted together, filament yarns consist of these lengthy fibers that can be produced as a single, solid strand. This method results in a smooth and strong yarn that often has a high luster.

The construction of filament yarns allows for certain desirable properties such as sheen, durability, and the ability to create fabrics that drape well. This is in contrast to some other types of yarns that might have a more textured or fuzzy appearance, which is characteristic of yarns made from shorter staple fibers. Therefore, the defining feature of filament yarns is indeed their singular nature, made by utilizing long filaments rather than multiple strands twisted together.