Before there was Tupperware, there was jadeite. Food storage containers were designed with flat lids for stacking and in shapes meant to fit in mid-20th-century refrigerators. Today they cost $45 to $150 (butter dishes, extremely rare, can cost even more). Part of Martha and Alexis Stewart’s jadeite collection, these pieces have found a home in the Arts and Crafts–style stable apartment at Skylands, Martha’s home in Maine.

Every collector is familiar with buyer’s remorse. So why are vintage-jadeite owners so immune to the what-was-I-thinking bug? Perhaps because it’s easy to remember what drew them to this pale-green glassware in the first place. Jadeite’s straightforward, honest shapes and fresh color embody American optimism in the mid-20th century. Moreover, as Martha says, “They work. They’re a collectible that’s usable.”

During the Depression, when housewives couldn't afford to waste a crumb, glassware companies turned out inexpensive jadeite containers for flour, salt, and other ingredients. Those with their original lids are some of the most desirable today.

Though somewhat hard to find, the Sunbeam electric mixer often sells for less than $100. The cake stand is contemporary. Made with vintage molds, it was sold through the Martha by Mail catalog in the mid-1990s.

Martha should know how usable it is. She has a large enough jadeite collection at her Skylands home, in Maine, to outfit a small chain of diners. Some 23 years ago, her daughter, Alexis, started the impressive collection during a cross-country road trip. Alexis has no idea how many pieces she owns, though her muscle memory is imprinted with their collective weight. “I used to pack them up and take them with me every time I moved,” she says. Over the years, parts of her collection have found their way to Martha’s place (“She feeds her cats out of my bowls,” Alexis says with a sigh) and onto the sets of Martha’s shows, where viewers have fallen in love with them.

Pictured: Almost every dish imaginable was made in jadeite. Vintage measuring cups and baking dishes are fairly rare today (in fact, this pie plate is a reproduction).

As a collector, Alexis was lucky. Or prescient. She bought most of her pieces before the late 1990s, when the cost of many jadeite items doubled and even tripled from one year to the next. Since 2003, prices have leveled, and fortunately, there is still plenty of jadeite to be found, often for less than $50 apiece at antiques shops and flea markets and on eBay.

Citrus reamers, center, are more plentiful; once given away to consumers with crates of fruit, they often can be purchased for $40 or less.

Glassmaking factories produced the occasional jade-green item as early as the 19th century. But jadeite really began taking off in the early 20th century, as consumer tastes in dishware shifted from post-Victorian frippery, such as floral and iridescent patterns, toward pure white, jet black, and jade green. These hues seemed completely modern despite the fact that their appearance and names evoked traditional materials, such as porcelain (milk glass), onyx (black), and jade. “Since the beginning of glassmaking over three millennia ago, glass has been used to resemble all kinds of things, including semiprecious stones,” says Tina Oldknow, curator of modern glass at the Corning Museum of Glass in Corning, New York.

Many glassware companies dabbled in jadeite, but only McKee and Anchor Hocking/Fire-King made complete dinnerware lines. The more delicate patterns, such as the squared-off Charm pattern from the 1950s, were for domestic settings.

Fenton Art Glass produced a wide array of jadeite items in 1921, and McKee Glass Company released the first complete line of opaque green dinnerware in 1930. Anchor Hocking and Jeannette soon followed suit, introducing several patterns for households, as well as heavier lines for restaurants. (The term jadeite, now broadly used to denote all similar green glassware, was originally claimed by Jeannette; McKee’s went by Skokie green, and Fire-King’s wares were called Jade-ite.) For the next 25 years, jadeite was manufactured by the ton -- and, lucky for collectors, much of it has survived without a chip in sight. “It was well made, so it didn’t break,” Martha says. “That’s why there’s still so much of it around.”

Thicker and heavier jadeite dishes were for restaurant use and are favored by many collectors. Restaurant ware comes in several designs, as is evident from the shapes of the cups.

Most collectors, including Martha and Alexis, like to amass the glass in all shades of green, but darker jadeite pieces are less common than lighter ones. Of the items stored in Martha's cypress cabinets, the ball pitcher, egg cups, and straight-sided "splash-proof" nesting bowls are the most coveted; the Swirl pattern mixing bowls are still fairly easy to find.