Qualities
Cotton is valued partly because it is the most elastic of all the vegetable fibers (although not as elastic as the animal fibers). Cotton canvas is able to withstand high temperatures, which allows it to be laundered repeatedly. Cotton canvas also readily accepts dyes. Because the center of the cotton fiber is hollow, air can freely circulate through the cotton fiber, allowing it to “breathe,” which enhances its properties as an apparel textile. (as noted, cotton also provides the basic cellulose material for some manufactured fibers such as rayon.) Nowadays cotton is combined with other fibers in blends such as cotton/wool, cotton/linen, and cotton/manufactured fibers, thus combining the best qualities of each fiber. With the advances in finishing techniques during the last 10 years many ways have been discovered to treat cottons chemically to enhance its qualities, Certain chemicals make it crisp to the hand or touch, as well as chemicals make it wrinkle free, flame-retardant, and waterproof. Treating cotton canvas can also make it resistant to mildew, and enhance its strength and luster.
Cotton classification
Cotton classification is the art of describing quality of cotton in terms of grade and staple length. Staple length is identified by using sight and touch and experience to determine the length of a representative bundle of cotton fibers from a bale of cotton. A good cotton classer must be able to tell consistently differences in length of 1/32 of an inch. Actually, a sample classified as 15/32 inch will have fibers ranging in length from 1/8 inch to 15/8inch.
The grade of cotton is determined by its appearance- more specifically, by its colour, leaf residue, and preparation. There are 40 grades for upland cotton. The predominant grade of cotton produced in the United States is strict low middling cotton. Strict in this case means “better than”.
Colour of cotton is described in terms that range from white to yellow. Colour is also described in terms of lightness to darkness: plus, light gray, and gray. This factor of appearance is a combination of grayness and the amount of leaf present in white-cotton grades.
Grading of American Egyptian cotton is based on ten grades. It is yellower in appearance than upland cotton and has a different appearance after grinning because it is done on a different kind of gin and has a higher leaf content.
Cotton is a commodity crop. It is sold by grade and staple length. Strictly low middling cotton is used in mass produced cotton goods and in cotton/synthetic blends. Better grades of cotton and longer staple cotton are used in quality shirtings and sheets.
More on production of cotton canvas
More on properties of cotton canvas
More on artist unprimed cotton canvas
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