Claim: Art silk is any natural fiber which resembles silk, but typically costs more to produce, the first successful art silks being developed in the 1990s of cellulose fiber (fibers made with ethers or esters of cellulose) and marketed as art silk or viscose.
Evidence: The first successful artificial silks were developed in the 1890s of cellulose fiber and marketed as art silk or viscose, a trade name for a specific manufacturer.