Filling (Warp Weft)
A filling is also known as Weft. The lengthwise, selvedge to selvedge horizontal, yarns carried over and under the warp. Filling yarns generally have less twist than warp yarns because they are subjected to less strain in the weaving process and therefore, must less strength. In pile-fabric constructions, such as velvet or velveteen, extra sets of warps are used to form the pile. A single filling yarn is known as a pick. See Selvedge denim, Core Spun Yarn and Morphology (fibre) Eco-Fashion Encyclopedia.