Silk is distinguished by a combination of certain qualities that make it unique and exceptional among other fibres. Silk has been revered and mystified since ancient times. Even the Roman philosopher and moralist Pliny the Younger in the 1st century argued that the people of the Roman Empire were too fond of silk. Natural silk is made from cocoons of silkworm caterpillars. This is an expensive material that, with proper care, looks luxurious for many years. The soft sheen of silk is a kind of ideal against which other fabrics are compared. And, of course, you want to keep your favourite blouse or silk dress for as long as possible.