Fulling refers to a traditional method of shrinking and softening woven fabrics by subjecting them to moisture, pressure, and heat. It is also known as "waulking" in Scotland, "tucking" in England, and "walken" in Germany. Other synonyms for fulling include "milling," "felting," and "knocking-up," which all describe the process of creating a denser, thicker fabric by matting or interlocking its fibers. "Fulling-mills" or "mill-houses" were the structures where fulling was carried out, often powered by water or windmills. Fulling has been used for centuries to improve the quality of textile materials, and it still has its place in the modern production of high-end fabrics.