If you burn Thai silk (a thread or two is enough) with a flame, it leaves fine ash and smells like burning hair. When you take the flame away it stops burning. If you burn imitation polyester silk with a flame, it drips, burns with a black smoke, and continues to burn after the flame is taken away . The three different sizes of digital images for each silk swatch on the World of Thai Silk web site make it easy for you to see the unique qualities of real Thai silk so you
probably
won't need to resort to the burn test