Following the invention of plastics by petroleum and chemical corporations, fibers could now be made synthetically. Advancements in fiber spinning actuators and control systems allow control over fiber diameter and shape, so Synthetic fibers, may be engineered with more precision than natural fibers. Fibers invented between 1930 and 1970 include nylon, PTFE, polyester, Spandex, and Kevlar. Clothing producers soon adopted synthetic fibers, often using blends of different fibers for optimized properties. Synthetic fibers can be knit and woven similarly to natural fibers.