A relatively thick cotton or linen fabric, named for its original use in sails. Generally, plain weave is adopted, and a few varieties use twill weave. Both the warp and weft yarns are multi-ply yarns. Coarse canvas, also known as tarpaulin, is commonly woven with 4 to 7 strands of 58-gauge (10-count) yarn. The fabric is strong and resistant to bending, and has excellent waterproof performance. It is used as a cover for transport vehicles, open-air warehouses, and tent covers in the wild, etc. The warp and weft yarns of fine canvas are generally 2 strands of 58 to 6 strands of 28 (10 count /2 to 21 count /6), and are used for labor protection clothing and supplies. After dyeing, it is also used as shoe fabric, travel bag, backpack and canvas case material, etc. Some fine canvas used for shoemaking can be woven into a double-layer structure, integrating the upper and lining of the shoe into one, which can improve the quality of the upper. In addition, there are rubber canvas, shielding canvas for heat protection, fire protection and radiation protection, canvas for paper machines, etc. Rubber canvas is required to have high strength in both the warp and weft directions, uniform density in the warp and weft directions, small differences in the interweaving gaps of the warp and weft lines, and no oil stains, which is conducive to the uniform penetration of rubber liquid during rubber application. The canvas used for paper machines should be thick and thick, with appropriate hardness and softness, a clean and smooth surface, and good moisture permeability. The raw materials of canvas have developed to chemical fibers and glass fibers, endowing canvas with better performance.