Ethyl Vinyl Acetate is used to impart hardness and strength to a candle. This additive is typically used to strengthen dipped taper candles.
It is not recommended for molded candles since it tends to cause the candle wax base to adhere to metal molds.
EVA is a rubbery plastic like material that takes time to blend into a candle wax. EVA will prevent mottling. Use is typically limited to less than 4%.