Natural fibres used for making twine include wool, cotton, sisal, jute, hemp, henequen, and coir. Plants are grown in sand, perlite, coconut coir and rockwool. It uses a by-product of coconut, namely, coir husk. Bristle coir is the longest variety of coir fibre. Sri Lanka remains the world's largest exporter of coir fibre and coir fibre based products. These can be a slab of concrete overlaid with a coir mat or artificial turf. The Indian coastal trade included goods such as coconuts, coir, pepper, cardamom, cinnamon and rice. It is known for cashew processing and coir manufacturing. Trade involved mainly cowrie shells and coir fiber. Kerala supplies 60% of the total global produce of white coir fibre. The first manufacturing factory for the coir mats was established in 1859. The coir is used to make brooms in Cambodia. It is home to fishermen, farmers, labourers, toddy tappers and coir spinners. The major use of white coir is in rope manufacture.