Carnival glass is an inexpensive presse glass, made as both functional and ornamental objects, always iridescent and found in a wide spectrum of colors. It was produced in the U.S., Britain, Australia, and several European and Asian countries from the early 20th century until the present. Carnival glass gets its iridescent sheen from the application of metallic salts while the glass is still hot from the pressing, then re-firing the glass. Glass workers sometimes refer to carnival glass as "dope glass" because the process of applying the iridescent coloring to the surface is called "doping".