Natural fibers include cotton, wool, hemp, silk and flax. The traditional materials are flax, hemp or wool. They grew many industrial crops such as flax, hemp and hops. Grimsby's port boomed, importing iron, timber, wheat, hemp and flax. Pliny the Elder describes the production of linen from flax and hemp. Fibres from pulpwood trees, cotton, rice, hemp, and nettle are used in making paper. Main cash crops include cotton, soybeans, peanuts, rapeseed, sesame, ambary hemp, and tea. The rags were from hemp, linen and cotton. Peasants commonly wore clothes made of hemp, wool, and ferret skins. The costumes were made with wool, linen, or hemp. Grass, rush, hemp, and sisal are all used in making rope. The port is important for palm oil, tobacco, cocoa, coffee, manila hemp and sago exports. Wool remained the most popular fabric for all classes, followed by linen and hemp. Harrelson is an enthusiast and supporter for the legalization of marijuana and hemp. A 100-gram portion of hulled hemp seeds supplies 586 calories.