How to Tell if Pyrex Is Vintage: Patterns and Marks

Pyrex is a trusted brand name of ovenware that has been in business for over a century, started as a part of Corning Glass Works. Vintage pieces are still used in today's kitchens. The easiest way to identify whether your piece is antique or vintage is to examine it.

How to Tell If Pyrex Is Vintage Using Patterns and Colors

Pyrex glassware made by Corning Glass Works was originally clear. In the mid-1940s, however, colored and patterned bowls and casserole dishes began appearing and are what many collectors seek today. Pastel shades of blue, green, pink, and more became common, although bright primary colors also had their time along with more muted earth tones. The Corning Museum of Glass's Pyrex Pattern Library and Pyrex Pattern Reference from Pyrex Passion have timelines that features popular colors and patterns through the years. Just a few notable ones include:

• Primary colors (red, yellow, blue, plus green) from 1945 to 1950
• "Snowflakes" (both white on blue and white on black) from the mid-1950s to late 1960s

• "Butterprint" farm scenes with male and female figures, roosters, and plants from the later 1950s to late 1960s

• "Gooseberry" featuring the berries on vines with leaves in the late 1950s through most of the 1960s

• "Town and Country" designs that featured abstract star-like designs in the 1960s

• "New Dot" featuring large colorful dots on white in the late 1960s

• "Friendship" highlighted deep orange and yellow roosters in the 1960s

• "Butterfly Gold" had a floral pattern in the 1970s

• "Autumn Wheat" showcased sheaves of wheat in the 1980s

Sometimes, groups of patterns are referenced together. For example, the "Gooseberry", "Butterprint Amish", and "Spring Blossom" patterns are all considered Americana patterns says BonAppetit. Limited patterns and promotional patterns were also released over the years, although they may be more difficult to find. Clear tinted glassware lines, like Flameware, Fireside, and Vision, were also common and their individual hues can help identify and date them. World Kitchen now owns the Pyrex brand and has reintroduced some of the popular patterns, so it is important to verify you have the vintage version.

Identify Pyrex Using Markings and Stamps

The color and pattern isn't the only thing that will help you determine whether your Pyrex is antique or vintage. Use the glass markings, stamps, and logos on the pieces themselves to identify when the glass was produced.

• The oldest Pyrex markings should be on the bottom of glass pieces and feature Pyrex in all capital letters inside a circle with CG for Corning Glassworks.
• A small figure blowing glass is included in some early stamps.
• "Made in the U.S.A." in all capital letters was added in the mid-1950s, along with a trademark symbol and/or trademark wording.
• The circle format ended and went to straight lines in the 1960s.
• Casserole dishes and bowls will have an inventory number included on the bottom stamp.
• Some pieces may include information on where/how to use them, such as "no broiling", which indicates they were made post-1970.

There have been numerous variations on the Pyrex markings over the years. If you do not see a backstamp on any of the pieces, especially the colored dishes, it doesn't mean it can't be Pyrex. Sometimes stamps would wear off in use and cleaning. Check with a local antiques appraiser or expert if you're unsure about whether your piece is vintage Pyrex.

What Is Pyrex Made Of?

Pyrex pieces are made of glass, although the type of glass has changed over the years.

• Pyrex ovenware was originally made of borosilicate glass due to its durability in heat. You can use identification markings, such as glass hue, date stamp, and more to tell if Pyrex is borosilicate; however, an expert can confirm.
• When opal glass was created in 1936, it was the catalyst for creating the colorful-hued bowls many collectors seek today, although it stopped being made for Pyrex in the 1980s.
• A soda lime mixture was made around the time of WWII to replace borosilicate.
• Various lines may have used other types of glass or mixtures, such as the aluminosilicate used in Flameware.
• The company stopped using borosilicate in the 1990s and went strictly to soda lime silicate glass for retail kitchen products, which has garnered some controversy among Pyrex users since it is not as heat-resistant as borosilicate.

Is Vintage Pyrex Worth Money?

Once you've determined your dish is both Pyrex and vintage, you might wonder if you should use it, put it aside for safekeeping, or attempt to sell it. If you want to buy or sell common patterns for individual pieces, you will likely pay or receive a reasonable price for a sturdy piece of kitchenware. Full sets in good condition are worth more, as are limited edition patterns which are difficult to find and can garner a higher price. Recent examples of various dishes and their worth include:

• The promotional "Navajo" patterned casserole dish sold for about $55 on Ruby Lane.
• A set of three "Amish Butterprint" dishes, a popular pattern, went for around $75 on eBay.
• Ruby Lane sold a 4-piece set of primary colored bowls for just under $100.
• A hard-to-find individual orange and black striped bowl sold for just under $500 on eBay.
• The incredibly rare "Lucky in Love" casserole dish was auctioned by Goodwill in 2017 for just under $6,000.

Collecting Pyrex Pieces

Home cooks still use many vintage Pyrex bowls and casseroles dishes in their homes today. If you're looking for pieces to add to your kitchen collection or put to use, check with older relatives, yard sales, and consignment shops to get the dish you need. Next, explore some vintage Corningware since it goes quite nicely into any kitchen collection.