U.L. Down - Ultra Light Down is used in women's and men's jackets. the concept is to make the lightest and warmest insulation layer available. U.L. Down jackets weigh less than a tee-shirt, blocks more wind, is warmer than even the heavist fleece jackets, and compress to the size of a water bottle. This outerwear can be used when warmth is critical, minimal weight is paramount, and space is at a premium.
Ultra-Light Weight - Term used to describe a fabric used in outerwear, which allows for a minimum pack volume and weight. Lightweight packable garments offer the most versatile weather protection. Some of these fabrics have a protective layer on the membrane, which provides durability. This means that the garments made from extra lightweight fabrics need no separate lining.
Unbalanced Stripes - A Stripe Design With An Irregular Spacing Between The Lines.
Uncut Corduroy - A Corduroy With The Pile Left Uncut. The Result Is A Strong Woven Fabric With A Warpwise Rib.
Under-press - To press the underside of a garment section during manufacturing to open the seams and give it shape.
Undrawn Yarn - Extruded Filament Yarn (or Tow), The Component Macromolecules Of Which Have A Low Degree Of Orientation. Note: Undrawn Yarn And Tow Represent Intermediate Stages In The Production Of Some Synthetic Yams And Staple Fibers Respectively.
Union Dye - A Dye, Or A Mixture Of Dyes, Which Will Yield An Apparently Solid Dyeing On The Fiber Mixture For Which It Is Devised.
Union Dyed - A Fabric With 2 Or More Fibers All Dyed In The Same Shade.
Union Yarn - A Yarn Made By Twisting Together Yarns Of Different Fibers.
Unripe Cotton - Immature Cotton
UPF (Ultraviolet Protection Factor) - The UPF rating indicates how effective a fabric is at blocking out solar ultraviolet radiation from reaching the skin. UPF ratings range from 15 to 50 with higher ratings indicating more effective blocking and therefore better protection for the wearer of a garment. Fabrics that test higher than UPF 50 are rated as UPF50+. UPF testing involves exposing a fabric to ultraviolet radiation (UVR) and measuring how much is tranmitted through the sample. Different wave-lengths of radiation in the UVR spectrum have different effects on human skin and this is taken into consideration when calculating the UPF rating. Factors that contribute to the UPF rating of a fabric are: *Composition of the yarns (cotton, polyester, etc) *Tightness of the weave or the knit (tighter improves the rating) *Color (darket colors are generally better) *Stretch (more stretch lowers the rating) *Moisture (many fabrics have lower ratings when wet) *Condition (worn and faded garments may have reduced ratings) *Finishing (some fabrics are treated with UV absorbing chemicals)
Upland Cotton / Uppers - A Type Of Cotton (gossypium Hirsutum) Which Forms The Bulk Of The World's Cotton Crop. It Varies In Average Staple Length From About 22 Mm To About 32 Mm.
Up-the-Roll - Describes the orientation of a pattern's direction. When looking at an up-the-roll pattern, the warp yarns are in the vertical direction, while the filling yarns are in the horizontal direction. Some industries and manufacturers prefer up-the-roll patterns, while others prefer railroaded patterns for their application. See also railroaded for illustration.
Urena - A Bast Fiber Similar To Jute, From The Plant Urena Lobata
UV Degradation - The breaking down of fibers or fabrics when exposed to ultraviolet rays.