Knee-highs are hosiery that covers the leg up to the knee. Typically worn by women in western society, these garments have become a global staple of modern semi-formal dress. They are generally made of nylon or other pantyhose material. Demand for such articles exploded during the 1960s and 1970s with the increase in popularity of the miniskirt. Knee-highs are also worn by many Catholic grammar schools and high schools. They come in many different colors and patterns, and are becoming more popular. They also keep legs warm in the winter months and are very comfortable to wear.