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.

The glass is produced in various translucent colors. Primarily amongst these are amethyst, marigold, cobalt, green, and red. Sometimes it is also made in opaque white which is called milk glass. A semi-transparent or translucent pale-green hue was also available before the widespread knowledge of radiation hazards. this glass was called Vaseline or uranium glass. Both of these contain traces of uranium salts which gives the glass a faint green glow when exposed to 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

Carnival glass has become a popular item for collectors. Some pieces are worth pennies, but hard-to-find pieces can bring in hundreds or even thousands of dollars, making for a wide range in prices. The market is jumping for this antique glass collectable.

The identification of the glass of carnival is as an operation much difficult one. Great part of the suppliers has not included the mark of the creator in their product, while the others have made therefore only for the part of the time that have produced the glass. In order to identify this glass, one must bind together the models, colors, splendor, edges, thickness and other factors from catalogue of the old supplier, other known examples, or the other material of reference. From many suppliers the produced near copies of the popular models of theirs available again, identifying it are a challenge also for an expert.