Showing posts with label doped. Show all posts
Showing posts with label doped. Show all posts

Monday, November 23, 2015

Stretched for Beauty



QUESTION: I recently purchased a beautiful plate at an antique show. The dealer said it’s stretched glass, but I don’t see how that’s possible since it’s a round plate. Can you tell me why my plate is called ‘stretched” glass?

ANSWER: Ever since it’s inception, the term stretch(not stretched) has confused people. It appears mistakenly on price tags in antique shops and in online descriptions. Because of the word “stretch,” People imagine a piece from the 1950s or 1960s that has been stretched to make it taller or wider, but stretch glass is entirely different.

Some people believe stretch glass is swung back and forth on a rod to make it stretch outward. Or, they think it looks like a strange type of Carnival or art glass, so it must be that. Neither is correct. Most of the time, people's first reaction is how beautiful the glass is, but they don't know anything about it.

On eBay there are over 28,000 listing for stretch glass and most are far from it. To collectors, stretch glass is iridescent stretch glass. It differentiates the glass from the common mistake of being considered swung glass. Forty to 50 percent of people think swung vases are stretch glass.

Created by several American glass factories from 1916 to the early 1930s, iridescent stretch glass is a pressed or blown molded glass. It’s shaped and formed—pressed or blown into molds—reheated and then sprayed with a metallic salt or dope, a procedure called  doping, while the piece is still hot. The glass blower then reheats the piece and this is when the stretch marks occur. The glass expands faster where the dope blower applied the dope, which causes a crackled, web-like appearance on the glass. Further shaping emphasizes these stretch marks. Some blowers often shape or "work" the glass a lot which emphasizes the stretch marks in the iridescence while others don’t work their pieces as much, resulting in finer stretch marks and are only satiny.

Collectors consider true carnival, stretch, and art glass with a shiny iridescence doped ware. The difference between them is when the glass blower applies the metallic salts to the glass. While glass blowers shape and form Carnival glass first and then dope it  to create a shimmering to slightly satin iridescent surface, they spray stretch glass  while the glass is molten hot, then reheat and reshape it to make the stretch marks. Another difference is that Carnival glass has a distinctive pattern in the glass mold, such as grapes, butterflies, or geometrical patterns on the inside, outside or on both sides of the glass. Stretch glass has little or no pattern and is very plain.

Confusion seems to set in when people are searching for stretch glass, especially since art glass also has both iridescence and stretch effects. Although art glass is from the same period as stretch glass, the chemicals in the glass make the difference. Additional stretch effects may be from doping the pieces and further shaping. Art glass is also much thinner and more delicate than stretch glass.

People also confuse freeform art glass, produced from the 1950s to the present and commonly posted on eBay, with stretch glass.

Companies that produced stretch glass included Central Glass Works of Wheeling, West Virginia, Diamond Glass-Ware Company of Indiana, Pennsylvania, Jeanette Glass Company of Jeanette, Pennsylvania, Vineland Flint of Vineland, New Jersy, and United States Glass Company of Pittsburgh, Pennsylvania.

The true difference between the stretch glass that different manufacturers produced was the unique colors. Tangerine is a popular color among collectors, along with red and ruby, which each cost more because of their popularity. Wisteria, a purple-colored glass is also popular. Opaque colors of stretch iridescent glass are rare and can be pricey.

The most common stretch glass color that can be found is celeste blue, as well as the topaz and pink. Blue was the  dominant color though, along with topaz, both of which were good selling items when they first appeared. Topaz was a good seller in the 1910s and 1920s because not everyone had electricity. This color catches the light and reflects it very well. There’s also a lot of Florentine green stretch glass out there as well and crystal stretch glass, which has a frosty white iridescence. With so many stretch colors out there including aquamarine, blue smoke, coral, custard, pink and white luster, beginning collectors are sure to find a favorite of their own.

Iridescent stretch glass not only comes in a variety of colors, but also a range of prices. Pieces that once sold for 25 cents to $1 can now be picked for $25 to $50, and even $10 to $15 for more common pieces.

High-end pieces, such as a Fenton No. 604 punch on a red stand, can sell into the thousands. One sold on eBay for $4,200. While the price may seem high, anyone can acquire a decent collection of stretch glass if they buy pieces in the $25 to $100 range.