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ANSWER: Carnival Glass is pressed glass—glass that has been formed by being pressed into a mold while in a hot molten form—that has had an iridescent coating applied. As it cools, it takes on the shape and detail of the mold. Once removed from the mold, and while still somewhat hot, the glassmaker sprays it with metallic salts in liquid form which gives it an "oil-on-water" multicolor appearance. He then refires the piece.
The Fenton Glass of Williamston, West Virginia, first produced carnival glass, which it called "iridescent ware," in 1907. The company called its first line Iridill and labeled it "Venetian Art." They wanted to mass-produce a product that could compete with the expensive, iridescent art glass made by Tiffany and Steuben. Though half a dozen companies, including Northwood, Imperial, Millersburg, Westmoreland, Dugan, and Cambridge, originally made it, Fenton did so longer than any of the others.
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Its eye-catching multicolor shimmer seems to change colors when viewed at different angles. Over the years, carnival glass has been dubbed "Taffeta," "Cinderella," and "Poor Man's Tiffany," as it gave the average housewife the ability to adorn her home with fancy vases and decorative bowls a prices she could afford.
But this new type of glass didn’t catch on with the public the way Fenton had hoped, especially since they tried pricing it higher than their regular pieces without the carnival finish. Unfortunately, most consumers didn't see carnival glass as quality glass and refused to pay higher prices for it. Other glass manufacturers soon began making carnival glass using the same iridization techniques. This overloaded the market and soon prices plummeted. To get rid of their excess inventory, carnival glass makers at first began giving it away to carnival owners to use as prizes, but later sold sample pieces to them in hopes that winners could then purchase additional items in the same or a similar pattern. Together all the manufacturers produced over 2,000 different patterns.
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Fenton's earliest patterns included Waterlily and Cattails, Vintage, Butterfly and Berries, Peacock Tail, Ribbon Tie, Wreath of Roses, Thistle, and Diamond and Rib. Among Northwood's first glass patterns were Waterlily and Cattails, Cherry and Cable, and Valentine, but Grape and Cable became their most popular. Millersburg collectors look for Hobstar and Feather, Blackberry Wreath, and Rays and Ribbons.
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Carnival glass is highly collectible. Prices vary widely, with some pieces worth very little, while other, rare items command thousands of dollars.
However, identifying carnival glass can be a challenge. It involves matching patterns, colors, sheen, edges, and thickness from information contained in old manufacturer's trade catalogs, other known examples, or other reference material. Many manufacturers didn’t include a maker's mark on their product, and some did for only part of the time they produced the glass. Since many manufacturers produced close copies of their rivals' popular patterns, carnival glass identification can be difficult even for an expert.
By 1925, carnival glass started to fall out of favor with Americans, and many U.S. glass companies quit producing it during the Great Depression.