The decade of the 1970s, like the 1960s, was one of extremes. Traditional plaids and prints, which were reintroduced, became popular at the same time that bold prints and geometrics, including Op Art and "psychedelic" patterns and colors, characterized the fabric and fashion. Synthetics were everywhere and made into everything, and phrases like "polyester knit" and "stretch knit" elicit visions of '70s staples that are unmistakable. The best way to...