Carnival glass is moulded or pressed glass to which an iridescent surface shimmer has been applied. It has previously been referred to as aurora glass, dope glass, rainbow glass, taffeta glass, and disparagingly as 'poor man's Tiffany'. The name Carnival glass was adopted by collectors in the 1950s as items of it were sometimes given as prizes at carnivals, fetes, and fairgrounds. However, evidence suggests that the vast majority of it was purchased by households to brighten homes at a time when only the well-off could afford bright electric lighting, as its finish catches the light even in dark corners. From the beginning of the 20th century, carnival glass was mass-produced around the world, but largely and initially in the U.S. It reached the height of its popularity in the 1920s, though it is still produced in small quantities today.

Carnival glass gets its iridescent sheen from the application of metallic salts while the glass is still hot from the pressing. It was designed to look like the much finer and much more expensive blown iridescent glass by makers such as Tiffany. Both functional and ornamental objects were produced in the carnival finish and patterns ranged from simple through geometric and 'cut' styles to pictorial and figurative. A wide range of colours and colour combinations, and scarcely used colours can command very high prices on the collector market.