Handy Guide to Pyrex Identification Marks, Patterns, & Value | LoveToKnow (2024)

Whether you remember them from your grandma's kitchen or collect them yourself, Pyrex dishes are just one of those iconic fixtures in American homes. Pyrex identification marks can help you understand how old a dish is, which pattern it might be, and even how much your vintage Pyrex might be worth.

Pyrex is a trusted brand name of ovenware that has been in business for over a century and started as a part of Corning Glass Works. Vintage pieces are still used in today's kitchens, so if you're rocking that 70s gold design, you're totally not alone. 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

The pattern is the first thing to check out on your Pyrex. 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 has a timeline that features popular colors and patterns through the years. These are just a few notable ones:

• Primary colors (red, yellow, blue, plus green) were popular from 1945 to 1950.

• Snowflakes (both white on blue and white on black) ruled from the mid-1950s to late 1960s.

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

• Gooseberry, featuring the berries on vines with leaves, was popular in the late 1950s through most of the 1960s.

• Town and Country designs featured abstract star-like motifs in the 1960s.

• New Dot featured 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.

Pyrex Identification Marks and Stamps

The color and pattern aren'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.

Vintage Pyrex Stamp and Logo

Flip over your piece and look at it carefully. It will have a stamp that can help you date it:

• 1940s and 1950s - 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.
• 1950s and 1960s - "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.
• 1970s and later - Some pieces may include information on where/how to use them, such as "no broiling", which indicates they were made post-1970.

What Do the Numbers on Pyrex Mean?

A lot of vintage Pyrex casserole dishes and bowls will have an inventory number or model included on the bottom stamp. This number is a super helpful clue for dating your pyrex, but it can be a little confusing. This handy Pyrex identification mark guide can help.

• Model numbers starting with 0 - Many older pieces have model numbers that start with 0, but this number doesn't really mean anything. Skip the 0 and move on to the model number after it.
• Pyrex model numbers on lids - Lids and bowls or casserole dishes often had matching numbers. Sometimes, the dish has a -B, and the lid has a -C.
• Final number - The final number sometimes indicates the capacity of the dish in pints, so a 2½-quart dish might have a number ending in 5.

Expect Variation in Pyrex Marks

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.

Most Valuable Vintage Pyrex Patterns and Pieces

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 (around $25). Full sets in good condition are worth more, as are limited edition patterns, which are difficult to find and can garner a higher price. Some even sell for thousands of dollars.

There are some vintage Pyrex pieces that have sold for record-setting prices. Check your cupboards for these super valuable patterns and pieces.

Lucky in Love Casserole Dish

What is the most sought after Pyrex pattern? It would be debatable, but a major contender for the title is Lucky in Love, a holy grail pattern from 1959 featuring hearts, shamrocks, and green foliage on a white background. An incredibly rare Lucky in Love casserole dish was auctioned by Goodwill in 2017, and it sold for just under $6,000.

Gypsy Caravan Mixing Bowl

A vintage Pyrex bowl's value can depend on a number of factors, including its size, pattern, and condition. The super rare Gypsy Caravan pattern in red on a white background is one collectors covet. An example in beautiful shape sold for almost $4,700.

Pink Tulip Oval Dish

Some patterns are more common in certain colors and virtually unheard of in others. In the case of the Tulip pattern, it's fairly easy to find in blue or brown but almost impossible in pink. This rarity adds a ton to the value. A pink Tulip pattern dish that may have been a prototype sold for over $4,400.

duch*ess Cinderella Bowl With Warmer

Promotional pieces can be extremely rare too, since they were usually made in small numbers to start out. A three-piece set with a Cinderella bowl in the duch*ess pattern, the matching lid, and a warmer (a stand that held a candle) was part of a give-away for the hostess at a party for Stanley Home Products. It sold for over $4,300.

Golden Trillium Casserole With Lid

Another promotional piece, a red casserole dish in the Golden Trillium pattern sold for almost $3,800. This pattern is very hard to find in the red color, and the dish was in excellent condition with only a little wear and its original lid.

Dianthus Casserole With Lid

A really rare pattern, Dianthus can be extremely valuable. This blue floral design is hard to find in good shape, so it goes for top dollar. A casserole with the original lid in perfect condition sold for about $3,000.

Nemacolin Country Club Zodiac Pyrex Dish

Vintage Pyrex pieces for specific companies or organizations can be super valuable, especially if they are rare patterns in really good shape. A zodiac design in red on white glass made for the Nemacolin Country Club sold for about $2,700. It had almost no damage and only light scratches from utensils.

Delphine Bluebelle Mixing Bowl

Unusual color changes or marks can make a vintage Pyrex bowl valuable. A Delphine Bluebelle bowl with a slight color change indicating a transition in two glass colors sold for over $2,500.

Pyrex Bankruptcy and How It Could Affect Values

In June of 2023, Instant Brands (the parent company of Pyrex) filed for bankruptcy. According to the company, this was due to falling sales, among other factors. The company wasn't closing its doors as part of the bankruptcy, but it does indicate a potential lack of stability.

As a result of the bankruptcy, sellers may be asking more for high-value Pyrex pieces. Many are listed on Etsy and eBay for thousands. For example, a set of mixing bowls in the Pyrex pattern Amish Butterprint was listed for $5,000 immediately after the bankruptcy. A similar set sold for about $1600 in March of 2023. In the long term, this inflation of prices could drive up values for the vintage Pyrex pieces. When antique collectors see something as scarce, it tends to be more valuable.

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.

Collect Vintage and Antique 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.