Weighted silk is silk which has been treated to restore or increase the weight lost during the process of degumming. This processing started in the 19th century, with vegetable-based solutions such as tannins or sugar. Chemical solutions based upon salts of lead or tin were then used, as well as silicate, phosphate of soda, and astringent extracts. These increased the weight considerably, but led to accusations of adulteration as the properties of the silk were impaired. Process and history Unlike most fabric/yard goods which are sold by the yard (or metre), silk is sold to the wholesaler by weight; however, as the first step in processing silk fibre is to "degum" it - removing the sericin from the fibre, a protein naturally produced by silkworms that coats silkworm cocoons - approximately one-fifth of the weight of silk fibre is lost, representing a significant drop in the saleable price of processed silk fibre. As such, silk fabric manufacturers would historically "replace" this lost weight with a 'filler', which would add weight to the fibre and thus make up the cost. Silk has an affinity for several metallic salts, the most common of which being iron, lead, and tin. It was discovered to be an easy process to return this weight lost in the degumming process by soaking the fibre in a bath of these metallic salts. This process was called 'weighting', and by increasing the weight of the raw silk, the merchant increased their profits. Weighting with some metallic salts did improve the drapeability of silk fabrics; however, merchants soon began adding more weight than the lost one-fifth, with the final weight of the fabric sometimes increased tenfold. In 1938, the U.S. Federal Trade Commission ruled that silk that weighted more than 10%, and black silk that weighted more than 15%, must be labeled 'Weighted Silk'. While silk is a strong and durable fibre, the weighting process is highly damaging to the finished fabric and resulting garments. If the garment is worn, it wears out quickly and is highly susceptible to damage from perspiration, salt, and tears; if stored away, it becomes brittle and begins to shatter along lines of wear at an expedited rate. The method of storage does not ameliorate the process of damage introduced by the fabric's weighting, with storage in cold, dry and dark areas doing little, if nothing, to prevent further damage. Examples of antique weighted