Carnival Glass, originally called Iridescent Ware, first came out in late 1907. It was not commonly referred to as Carnival Glass until the 1950s, though, when collectors started calling it that. These pieces were typically made from extremely ornate glass pieces, characterized by the myriad hues of their sheens. Their luster was achieved by applying metallic salt sprays to the glass before it had completely cooled down.

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 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.

Millersburg glass Company is one of the largest producers of this kind of glass. Crystals were the first glass products of the company. But they decided to go for iridescent glassware to ride the wave of enthusiasm. So, during the early 1910, the line of Radium Glassware was brought out by Millersburg glass Company.

Carnival glass is a collector's item. Prices of these glasses vary wildly from a few dollars to thousands of dollars. Carnival glass has become antique glass collectible and there is a good active market for it.

It is very hard to identify carnival glass. Most of the time, the makers didn't mark their work, others only marked them part of the time. To figure out who made the glass one has to match, patterns, colors, sheen, edges, thickness and some other factures from old trade catalogs, examples of prior work or a reference material. Many manufacturers made dlose copies of rivals popular works to. So even for an experienced expert this is a hard task.