Natural fibers include cotton, wool, hemp, silk and flax. They sowed wheat, barley, rye, and flax. The traditional materials are flax, hemp or wool. Farmers surrendered their grain, fodder, wool, flax, and hemp. They grew many industrial crops such as flax, hemp and hops. This has been established for flax and sunflower seeds, as well as soy beans. Flax and hemp resist rotting, but wool is softer and more comfortable. Grimsby's port boomed, importing iron, timber, wheat, hemp and flax. Whether made of flax or hemp, they had rope. Cemeteries in the Carpathian Basin also yielded scraps of canvas made of flax or hemp. Pliny the Elder describes the production of linen from flax and hemp. Cotton, sugar beets, potatoes and flax were also major crops. Dams and canals were repaired, and wheat, barley, flax, and cotton production increased. In addition to cereals, cotton, sugar beets, potatoes, and flax were also major crops. Linen fibers look like the strong fibrous strands of the flax plant.