Textured fabrics are generally plain in appearance but have an irregular tactile look and touch. Texture can be added to a fabric by using textured yarns, by combining different types of yarns to create texture, or by incorporating slub yarns. Slub yarns have a very definite texture and often give an organic appearance as they mimic naturally occurring weaving irregularities such as cotton seeds in the yarn, or knots tied during the process of hand weaving.