Dupioni and shantung are plain weave crisp silk fabrics, produced by using fine thread in the warp and uneven, thicker yarn for the weft. This creates fabrics with a highly-lustrous and textured or “slubby” surface. Dupioni and shantung are similar, but dupioni is slightly thicker, heavier, and has a greater slub count. Both have a high sheen and are often constructed with different color warp and weft yarns to create an iridescent effect.