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.

Made as both functional and ornamental objects and found in a wide array of colors, carnival glass is an inexpensive pressed glass, often called dope glass by glass factory workers because of the process of applying the iridescent coloring, which is known as doping. Its production can be traced back to as early as 1907, with many, many different pieces in over 150 distinct patterns. It did not, however, command the expected prices, and was subsequently discounted heavily.

This glass is made in many translucent colors like primarily amethyst, marigold, cobalt, green, and red. It is also made in opaque white, which is referred to as milk glass. Before the hazards of radiation were well known, the glass was also made in semi-transparent or translucent pale green and was named as Vaseline or uranium glass. Vaseline glass and uranium glass contain traces of uranium salts in the glass which can make a faint green glass glow in reaction 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 collectible .

Identification of carnival glass is very difficult task. Most of the manufacturers did not include a maker’s mark in their product, while the others did so only for part of the time they produced the glass. To identify this glass, one has to match patterns, colors, sheen, edges, thickness, and other factors from old manufacturer’s trade catalogs, other known examples, or other reference material. Since many manufacturers produced close copies of their rivals’ popular patterns, identifying it is a challenge even for an expert.

At the time of introduction in late 1907 the carnival glass was called as Iridescent Ware. The prices of this glass vary widely depending on their quality and availability. This glass is a highly collectible item with some of the pieces worth very little, while other, rarer items command thousands of dollars. There is a very active market for this item since it has become an antique glass collectible. Among the greatest producers of this type of glass was millersburg glass in Ohio. It is very hard to identify these products, because the makers didn’t consistently mark their work.