Kasavu is a technique used in handlooms of Kerala, with very fine threads of gold or silver used in weave to make border lines and designs on silk and cotton fabrics. This technique later spread to most of India and the Kasav technique was developed for many other fabrics across India. White or off-white cotton cloth with Kasav borders that originated in the South Indian state of Kerala is now famous as Kerala saree is believed to be first form of use of Kasav technique.