The majority of T-shirts are made of 100% cotton, polyester, or a cotton/polyester blend. Environmentally conscious manufacturers may use organically grown cotton and natural dyes. Stretchable T-shirts are made of knit fabrics, especially jerseys, rib knits, and interlock rib knits, which consist of two ribbed fabrics that are joined together. Jerseys are most frequently used since they are versatile, comfortable, and relatively inexpensive. They also are a popular material for applying screen prints and heat transfers. Some jerseys come in tubular form, simplifying the production process by reducing the number of seams. Rib knit fabrics are often used when a snugger fit is desired. Many higher quality T-shirts are made of durable interlock rib knit fabrics.