Oatmeal Cloth
A heavy, soft linen fabric with a pebbled or crepe effect.
O.F., or A.F.
For Other Fibres (Altre Fibre), can be found on the Composition label of fabrics containing recycled materials. Many of the fabrics produced in the Italian area of Prato are made using yarns spun from blends of reclaimed wool (and, of course, other fibres.).
Oilcloth
Any fabric treated with linseed-oil varnish to make it waterproof. It comes in plain colors and printed designs and is most commonly used for table covers or shelf-covering. It has now been widely replaced by plastic-coated fabrics.
Ombré
A color effect which is changeable in shade from light to dark, generally produced by using warp yarns of different tones.
Ondule
A general term for plain-weave fabrics of silk, cotton, or man-made fibre having a wavy effect produced by weaving the warp or filing, but usually the filling, in a wavy line. An ondule reed is generally used to produce this effect, often in a leno weave to emphasize the wave. Ondule is used for dress fabrics.
One-ply Yarn
One strand of thread is used to form the yarn that is woven into terry loops.
Open-end
An industrial, highly efficient type of yarn spinning technology that utilizes turbine machinery. Faster and less expensive than the original ring-spun system, it produces denim fabrics that have a more regular, flatter appearance. Often referred to by the initials O.E.
Opening
A preliminary operation in the processing of staple fiber. Opening separates the compressed masses of staple into loose tufts and removes heavier impurities.
Optical Brighteners or Optical Whiteners
Chemicals that make fabrics appear to reflect more light than they really do, to make them brighter (they convert ultraviolet light to visible light in the blue region). They are sometimes used in the manufacture of fabrics and are often included in the formula of many detergents sold for home use.
Organdy
A very thin, transparent, stiff, wiry, muslin fabric used for dresses, neckwear, trimmings, and curtains. Swiss organdy is chemically treated and keeps its crisp, transparent finish through many launderings. Organdy without chemical treatment loses its crispness in laundering and has to be restarched. Organdy crushes or musses but is easily pressed. Shadow organdy has a faint printed design in self-color.
Organic Cotton
Cotton grown where toxic chemicals have been eliminated in all growing process steps. Living soil (defined as being free of toxic chemicals for three years) is the basis of an organic farm and organic farmers have proven when plants are healthy they are able to resist insects, weeds and disease.
Organza
A stiff, thin, plain-weave fabric made of silk, nylon, acrylic, or polyester, organza is used primarily in evening and wedding attire for women.
Organzine Yarn
Two or more threads twisted in the singles and then plied in the reverse direction. The number of turns per inch in the singles and in the ply is usually in the range of 10 to 20 turns. Organzine yarn is generally used as a warp yarn.
Orientation
In linear polymeric structures, the degree of parallelism of the chain molecules.
Osnaburg
A coarse cotton or polyester/cotton fabric, often partly of waste fiber, in a plain-weave, medium to heavy weight, that looks like crash. Unbleached osnaburg is used for grain and cement sacks, and higher grades are used as apparel and household fabrics.
Ottoman
Heavy, large, filling rib yarns, often of cotton, wool, or waste yarn, covered in their entirety by silk or man-made fiber warp yarns characterize this fabric used for women’s wear and coats.
Ounces per sq. Yard
A measurement of fabric weight, a weight usually asked for when making a comparison to competitve brands.
Overall
A one piece garment style usually made from denim or canvas. It is a paint with a bib top and suspenders over shoulders and back. Originally a work wear product.
Overdye
Fabric dye process on denim fabrics. Most frequently used on indigo or black denim fabric which is overdyed black. Dyeing one color over another.
Overedge / Overlock Stitch
A stitch formation where the stitch forms a triangle of thread around the edge of the seam. There are 3 categories of the 500 Stitch Class -- Single Needle Overedge; Two Needle Overedge; and Safety Stitch.
Oxford Cloth
A soft but stout shirting fabric in a modified basket weave with a large filling yarn having no twist woven under and over two single, twisted warp yarns. The fabric is usually made from cotton or polyester/cotton blends and is frequently given a silk-like lustre finish.
Originally made in Oxford, England, it is a plain weave fabric where 2 or more filling yarns pass over and under 1 or more parallel warp yarns. It is possible to have 2x1, 2x2, 3x2, 4x4, or 8x8. Used in dress shirtings where the warp is a color and the filling is natural. Also very popular in nylon for outerwear jackets.
Oxidation
Where oxygen and another substance chemically join. Occurs when indigo yarn comes out of the indigo bath between dips, and is critical for the dyestuff to penetrate the fibre.