2.5mm in size, made of Acetate. Sold by the yard.Italian Luxury Soutache works well with rayon soutache. Similar size and sheen. They may be used together for great results. Acetate looks like silk and feels just as soft. It has a lovely drape with minimal static cling and no issues with pilling.The fabric is resilient to mildew, moths, and shrinks only a little. Acetate will remain colorfast during dry cleaning and against perspiration stains. Although the material can be washed in water and dries off quickly, dry cleaning is a better option for maintaining the quality.