Carnival glass is pressed glass that has been coated with a sodium solution and fired to give it an exterior lustre. First made in America in 1905, it was produced until the late 1920s and had great popularity, for unlike costly art glass produced by Tiffany, carnival glass could be produced at a small cost. Companies mainly responsible for production in America include Fenton Glass Co., Northwood Glass Co., Imperial Glass Co., Dugan Glass Co., and Millersburg Glass Co. Carnival glass has been highly collectible since the 1950s and has been reproduced for the last twenty five years.