Textiles are fabrics made from weaving together natural or synthetic yarns or fibers. Conventional synthetic fabrics, battings, and fibers usually are derived from nonrenewable petrochemicals, which don't biodegrade and are difficult to recycle. These include polyester, nylon, acetate, and acrylic. Some natural plant fibers, derived from sustainable materials without the use of petrochemicals, are fully renewable and biodegradable. Natural textiles include cotton, hemp, bamboo, and tencel—wood pulp harvested from sustainably farmed trees. Other sustainable options include natural and renewable wool from merino sheep, as well as recycled fabrics. But even plant-based fibers can have large environmental impacts: Conventional cotton is responsible for more than 25 percent of the world’s insecticide use, despite accounting for only 3 percent of the world's agriculture.