Medal, marketing sample, British Viscoid Co. Ltd., undated, c.1898; Viscoid, 37.9mm (4.4 mm thick), 7.32 grams. Synthetic fibers took a major step forward in 1892 when three English chemists developed a method of treating cellulose to produce a substance they called viscoid. The British Viscoid Co. Ltd. formed in 1898 to produce solid viscose items. In making viscoid, solid aggregates are formed by mixing viscose with minerals, hydrocarbons, etc.; products are then cast into convenient forms.