Glossary
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Y
Yarn: Generic term for a thin, long, continuous strand of textile fibres, filaments, or material in a form suitable for knitting, weaving, or otherwise interwining to form a textile fabric. An assembly of substantial length with a relatively small cross-section, made from fibres and/or filaments into a long, thin strand. Assemblies of fibres or filaments are usually given other names during the stages that lead to the production of yarn, e.g. tow, slubbing. sliver, or roving. Except in the case of continuous filament or tape yarns, any tensile strength possessed by assemblies at these stages is generally the minimum that can hold them together during processing.
Yarn Spinning: The process of joining together short or staple fibres by drawing them from the fibrous mass and twisting them together. Spun yarns are produced in this way from the natural fibres such as wool, flax and cotton. Man-made fibres also are produced in this form, after chopping up a tow of continuous threads. The fundamental operations of spinning yarn by traditional methods are carding, drawing and inserting twist, followed by winding.
Yarn Twist: The number of turns of twist per unit length yarn. It is the twist in the yarn, which helps the fibres to hang together and the important factor is the angle of twist. This is the angle which the fibres make with the long axis of the yarn. However, it is more convenient to refer to the twist in turns per centimetre.
As the amount of twist is increased in yarns they become stronger as fibre slippage is lessened, but when maximum strength has been reached, any further twisting tends to weaken the yarn. However, it is not necessary for all yarns to be twisted to the degree necessary to achieve maximum strength. Some yarns are required with soft and desirable characteristics requiring less twist, and thus having a somewhat reduced strength.
Yolk: The oily fat surrounding the wool fibre in sheep, composed largely of wool fat, or lanolin, plus dried perspiration or suint.
Yorkshire Tweed: A fabric made of reworked wool, low-grade wool, or a mixture of wool and cotton, in imitation of Tweed.
Yuzen: A secret Japanese process of dyeing a painted fabric in which fidelity of pattern, boldness of line, and rich colouring is retained. Habutai, silk crêpe and velvet are examples of fabrics used.
Yuzen Birodo: A velvet fabric made by applying the yuzen process and then cutting away the pile with a small, sharp chisel, cutting the strong lines and shadows deeply and the delicate portions lightly.
