At the time of introduction in late 1907 the carnival glass was called as Iridescent Ware. However, people started using the name carnival glass only after collectors in the 1950s began to refer to it as such. This innovative glassware made in highly patterned moulds had a vivid metallic sheen of changing hues on pressed glass articles. Iridescent Ware got the metallic sheen from a special spray of metallic salts on the glass while it was very hot.

Carnival glass is a colored, inexpensive pressed glass that was used to make both functional and ornamental objects. It can be found in a wide range of iridescent colors. Carnival glass is sometimes called dope glass by glass workers because doping is the process of applying the color to the glass surface. Carnival glass production started in 1907. It was used in production of many different pieces and in more than 150 patterns. However, since it did not command the prices expected, it was subsequently discounted.

This glass is available in many translucent colors like primarily amethyst, marigold, coblat, green and red. It is also made in opaque white which is also referred to as milk glass. This glass was also availale in semi-transparent or translucent pale green and was named as Vaseline or uranium glass before the harmful effects of radiation were known. Vaseline glass and uranium glass have small amount of uranium salts which make faint green glass glow on reaction with UV light.

One of the largest producers of this kind of glass was Millersburg glass Company, Ohio. The first glass products of the company were crystal, but the Millersburg plant decided to ride the wave of enthusiasm for iridescent glassware. Thus, in early 1910, the Millersburg Company brought out its line of Radium glassware.