Doupioni [doo-pee-oh-nee] Also spelled douppioni, dupioni [doo-pee-ohn] or dupioni, is a silk fabric. It is so called because two cocoons (or dupions) that are reeled as one. This created a very strong but slubbed, irregular yarn. Silk fabrics called shantung or pongee are also made from doupoini yarn. The plain weave fabric made of this yarn and labeled Doupoini will always exhibit this slubbed texture. It is considered slightly inferior to ordinary raw silk, but is very strong and with slight give. It is used for fine apparel and upholstery.
As you can see from the pictures, there is some variation from one fabric to the next in the amount of texture. Also, the fabric is very prone to raveling - something to consider when choosing it. Imitations are made in rayon and synthetics under different names such as cupioni.