by Pamela Siegel
Vintage Pyrex glassware, a staple in American kitchens during much of the 20th century, gained momentum in the collectible kitchenware category during the early 2000s. Many talented home cooks have been remembered for their favorite Pyrex mixing bowl or a beloved casserole dish used for Sunday suppers. Some of these have been passed from generation to generation spurring nostalgic collecting of matching sets. Other collectors are inspired by the colors and patterns to curate eye-catching displays. The first Pyrex, however, was crystal clear.
Pyrex History in Brief
Pyrex kitchenware – first produced in 1915 by Corning Glass Works in Corning, New York – was a “necessity is the mother of invention” creation. Glass resistant to high temperatures was already being produced by Corning prior to that time. As it was being tested for use in industrial containers, according to Smithsonian Magazine, a Corning physicist cut the bottom off a battery jar and took it home to his wife. After having ceramic dishes crack in the oven previously, the homemaker was pleased with this improvised dish. A new Corning product was born, but it didn’t come cheap.
The first 12 Pyrex products, which are now considered to be antiques since they are more than 100 years old, were clear glass items ranging from casserole dishes and pie plates to custard cups and loaf pans. New variations were introduced over time, including multiple sizes of the most popular glass ovenware pieces. The glass changed from borosilicate to a new aluminosilicate formula in 1936. As production processes were refined in the 1930s, Pyrex products became more affordable, and their use became more widespread in American homes.
In the 1940s, solid colors on opal glass were added to the company’s lines. In 1956, patterns decorating Pyrex glass were introduced and became commonplace moving forward. These decorated pieces now have a huge following among vintage kitchenware collectors.
Vintage Pyrex Primary Color Bowls, late 1940s
How to Get Started Collecting Pyrex
Since these items were so popular when they were new, collectors shopping for vintage Pyrex find a variety of choices while perusing estate sales, online listings, and thrift shops. The plain, clear glass pieces fall off the radar for many collectors unless they are unusual prototypes or rarities.
Most buyers focus on hues and patterns when seeking Pyrex beginning with the opal glass pieces decorated with solid colors dating to the late 1940s. These include nesting mixing bowl sets with three or four different sizes. The Primary Color Bowls, also known as the 400 Series Color Bowls, is a set consisting of blue, red, green, and yellow in graduating sizes. For many enthusiasts, this set is the foundation Pyrex collecting is built upon.
There are two main styles of vintage Pyrex bowls: round and “Cinderella.” Cinderella bowls have grips on either side that can also serve as pour spouts. Both styles were decorated with dozens of different patterns and colors from the 1950s through the early 1980s, as shown on Pyrex Love.
Vintage Pyrex Cinderella Bowls including Friendship pattern, early 1970s
Some of the most common patterns are Butterprint, Daisy, and Gooseberry. Because they are more plentiful, any of these can be a reasonably priced starting point for growing a pattern-themed collection. Several rarities in these patterns can be tracked down, too. Those, along with hard-to-find designs like Gypsy, Duchess, and Blue Dianthus, are more costly.
While bowl sets rank high in the Pyrex popularity contest, many other patterned pieces were also marketed by the company. These include “Bake-Serve-Store” casserole sets, divided serving dishes, and refrigerator dishes for stowing leftovers. All these came with either clear or opal glass lids when they were new, depending on the item. Collectors often find one piece and then enjoy the challenge of putting together complete sets.
Vintage Pyrex Butterprint refrigerator dishes, late 1950s
Because the values vary so widely, it is important to research each Pyrex item you purchase individually. For instance, if you acquire a bowl set in the Butterprint pattern (sometimes called Amish Butterprint), be sure to check all the sizes. A single 8-ounce bowl in this pattern can be worth thousands. Colors matter, too, since orange Butterprint is several times more valuable than turquoise blue.
Pryex mark, 1950s
How to Identify Vintage Pyrex
Both antique and vintage Pyrex items have a raised backstamp molded into the glass. These marks changed over time, according to The Pyrex Collector, so they help collectors identify pieces in addition to dating them. The oldest mark found on clear ovenware pieces is a circle with Pyrex in a serif typeface and the CG logo of Corning Glassworks. In 1919, the word “patented” was added to the mark. This backstamp was used through 1924. A Corning mark with a figure of a glassblower was used on the first opal glass made in the mid-1930s (although these were dishes made for military use rather than kitchen items.)
Marks used on opal glass kitchenware from 1945 onward read Pyrex in uppercase lettering with T.M. REG. and U.S. PAT. OFF. in a circular pattern. In the 1950s, a registered trademark symbol (R within a circle) was added below the name along with Made in U.S.A. The backstamp configuration changed again in the late 1960s so that the wording was stacked rather than circular. By the mid-1970s, metric units were noted in the marks and “by Corning, Corning, NY USA” was added below Pyrex.
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Written by:
November 15, 2022 Updated 02:06 PM
As a freelance writer, Pamela Siegel covers lifestyle topics ranging from antiques and collectibles to interior design and everything around the home. Her work appears on The Spruce where she shared tips and research as the site’s antiques expert for many years. She also writes for House Digest, Kovels Antique Trader, Worthpoint, and Mashed. In addition to penning thousands of articles for online resources and print-based pubs, Siegel authored several books including “Warman’s Costume Jewelry” and “Buying & Seling Antiques and Collectibles on eBay.” She also shares her expertise with other magazine writers along with doing television, radio and podcast interviews. As often as possible, Siegel loves shopping flea markets and estate sales for her next great find, home decorating, foodie pursuits, and exploring the world on cruise ships.
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