A silk comforter (絲綿被) is a bed covering, most often used as a duvet, and also commonly referred to as a silk duvet, silk quilt, or silk blanket. Originally used and made in China, since the late 20th century, silk comforters have become more common in Western market areas. Their increasing popularity stems from a combination of factors, including their thermal properties, their light weight, and their natural hypoallergenic properties. The opening of the Chinese market to the world since the 1990s has also played a significant role in the spread of silk comforters, as China is both the world's biggest silk producer and silk comforter manufacturer.