Dupioni silk is an exquisite fabric with a lustrous appearance on both its front and back sides. Typically, this particular silk is made from multiple colors of fabric woven together, and the final result is a rich, iridescent material that changes depending on the light. When working with this fine fabric, it can be difficult to decide which side is right and which is wrong. Fortunately, following a few simple steps will help you immensely in deciding which is the right side of your Dupioni silk.
Look for small bumps in the fabric. These bumps are referred to as "slubs" and they originate from bonding of the fibers during weaving. Typically these bumps are more pronounced on one side, and that side is often labeled the right side.
Brush your hand over the fabric. Examine whether one side feels bumpier than the other side. This method can often yield better results than Step 1 when looking for bumps. Whichever side has more "slubs" will be the right side.
Expose your fabric to different lighting environments. See whether or not one side shimmers more than the other. Again, this would be the side most often considered the right side.