Hemp has been used for thousands of years in products like rope, paper, and textiles. In other countries, hemp is cultivated for many uses, including the creation of hemp fabric. It’s absorbent, tough and renewable, which makes it very appealing to environmentally-conscious shoppers. In the U.S., industrial cultivation of hemp is not allowed, due to its relationship to marijuana.
Cannabis sativa is the hemp variety grown for industrial uses and has little delta 9 tetrahydrocannabinol (THC), the psychoactive compound found in marijuana. C. sativa indica, the type used for recreational and medicinal drugs, has a much lesser fiber quality and isn’t suited for manufacturing. Canadian varieties of hemp that are very low in THC have been developed, lifting bans on cultivation of the plant there. The acceptable level in Canada is a THC content of no more than 0.3%, compared to marijuana’s 5 to 20%.
The first American flag was made from hemp fabric, as was the first pair of Levi's® denim jeans. For many years, sails and canvas used on ships were made from hemp, as were many varieties of rope. Hemp fabric can be entirely made from the plant or blended with other fibers including cotton and silk. The long fibers have a high yield, up to 10% more than cotton or flax.
When woven, hemp has a texture similar to linen, which makes it ideal for suits and handbags. It takes dye well, due to its absorbent properties and is hard-wearing. This makes it ideal for tough casual clothing and bedding. Hemp fabric is resistant to UV light, making durable and attractive upholstery fabric, and can also be knitted into jersey, fleece and terry. The fibers have antimildew and antimicrobial properties.
Caring for hemp fabric is simple, since it is machine washable in both warm and cold water and can be machine-dried, or dried outside on a clothesline. Fabric softeners can leave a film that interferes with its absorbency, so if the fabric is being used for diapers, softeners are not advisable. Bleach will weaken the fibers, and should not be used.
Supporters of industrial use of hemp in the US have encouraged shoppers to purchase hemp clothing, health foods and other products to create demand. Its sustainability and the variety of products in which it can be used are a strong talking point for their platform. Europe, China, Canada and Russia all permit cultivation under license. As of 2011, US consumers mostly have to purchase imported hemp fabric items.