How to differentiate canvas fabrics?

I believe that many people have worn canvas shoes, for so many years you wear canvas shoes, and understand how much canvas fabric?

  Canvas width: refers to the weft width of the canvas, in common use "inch" indicates, such as "47", in the domestic commonly used "centimeter" or "cm In China, "centimeter" or "cm" is commonly used, such as "120cm". Canvas is a thicker cotton or linen fabric, named for its use in sails. Canvas is multi-strand weaving, so the texture is firm, wear-resistant, compact and thick, generally more plain arrangement, a small number of twill arrangement, warp and weft yarns are used multi-strand.
 With the progress of science and technology, textile technology has been greatly improved, the types of canvas gradually increased, more widely used. Understand the canvas fabrics have to start from the grammage, width, yarn count three aspects. Canvas weight: refers to a square meter of fabric weight grams, woven canvas fabric with "ounce", "an" or "OZ" knitted canvas general use of grams of weight (g/m2), it's conversion is 1 ounce is equal to 28.375 grams of cloth in the weighing machine is generally 28.35 grams, with the yarn count and fabric density of the warp and weft of the fabric, the thicker the density of the yarn is the more dense the cloth is thicker, the more the grams of weight is greater.

Canvas yarn: yarn support in short, that is, the degree of thickness of the yarn, China's current common or "British system" that is: a pound (454 grams) of cotton yarn (or other components of the yarn), the length of 840 yards (0.9144 yards / m), the fineness of the yarn for a. If a pound of yarn, the length of the yarn, the fineness of the yarn for a. If a pound of yarn, the length of the yarn, the fineness of the yarn for the fabric. If a pound of yarn, its length is 10 × 840 yards, its fineness is 10, the yarn count method of indication of the British system of indicating the symbol is the letter "S" single yarn is indicated: 32 single yarn ---- is indicated as: 32S yarn is indicated as: 32 strands (two and twisted) both for: 32S/2, 42 The method of showing 32 strands is: 32 strands (two twisted) is: 32S/2, 42 strands 3 twisted is: 42S/3.