Twill fabric is a type of textile weave characterized by diagonal ridges or lines on the surface of the fabric. The diagonal pattern is created by interlacing the yarns in a way that forms a pattern of diagonal lines or ridges on the fabric surface.

Twill fabrics can be made from various fibers such as cotton, wool, silk, or synthetic materials. The weave can be tight or loose, and the diagonal pattern can be more or less pronounced, depending on the yarn thickness and tightness of the weave.

Twill fabrics are commonly used in a wide range of apparel and home decor products. For example, denim is a type of twill fabric used for jeans, while gabardine is a twill fabric often used for suits and trousers. Twill is also a popular choice for upholstery and drapery because of its durability and strength.