When turn-of-the-century dandy decorator Henry Davis Sleeper started to outfit his Gloucester, Massachusetts, home, Beauport, in 1908, he famously assembled a wall of glass vessels not distinguishing between the luxurious and the rare and the mass produced and the cheap. Next to two-penny Depression glass, made by the hundreds in factories, sat rare 18th-century handblown Venetian and Czech treasures. Sleeper proved that glass of any kindboth rare and inexpensivecan be deployed to brilliant effect in your home, and his Beauport estate remains a touchpoint for many interior designers today. Skip SectionJump toWhatever your preferred period or aesthetic, there is some form of decorative glass waiting for you, whether its a family heirloom, an estate sale score, or a serendipitous thrift store find (it happens!). But how do you go about identifying antique and vintage glassware? For starters, you have to know what to look for. For help, weve consulted the experts and broken down a few vintage-glass-collecting tips and names to know. Who knows? There may be treasure in your attic.How to Identify an Antique or Vintage GlassMassimo Ravera//Getty ImagesDo your research so you know what to look out for when glass shopping. Like anything, glass has followed trends through time. At one point the thinner the walls of a vase the more valuable. Later, thicker, more highly textured surfaces were favored. Fashionable colors, patterns, and methods of decoration ebbed and flowed with each decade. The only way to tell if something might be of value today is through close observation. Small irregularities, like a glass knob at the bottom of a vase or cup, can indicate a piece was handmade. Spy a seam? It was likely mass-produced. Watch a glassblowing view on YouTube to see where glassblowers hold, mold, shape, and cut the glass while its malleable. Aspects of a cup or vase's fabrication will often show themselves in its finished form. If a glass is too regular and too easily replicated then it might not be very valuable. If glass is signed, which is an easy first step towards ascertaining its value, that signature will usually show itself on the underside of an object. I recommend handling and close-looking, affirms Samantha Robinson, director of decorative arts and design at Heritage Auctions. Any collector, regardless of experience level, should examine the quality of the glass itself its weight, the thickness of its walls, its color, its surface before turning to any mark or signatureMarks or signatures vary from firm to firm and also within a single firms output over the course of years or even decades. Courtesy of Heritage AuctionsLoetz Argus Glass Vase designed by Koloman Moser, circa 1902.Also familiarize yourself with styles and periods. Often craftspeople will reference or copy styles that originated a century or more before, but there are always distinctions between a period original and something in the style of or just plain fake. Generally, the later version is slightly more crude with fewer details. You can train your eye by visiting auction previews or museums with in-depth collections like Corning Museum of Glass in Corning, New York, Chrysler Museum of Art in Norfolk, Virginia; Tacoma Museum of Glass, or the Morse Museum in Winter Park, Florida.If after your studies you happen across something of interest, dont hesitate to confer with an expert. While collectors have a tremendous amount of information at their fingertips literallyon the Internet, not all of it is correct. The best way to confirm authenticity is to reach out to an expert, such as an auction specialist, who can examine the piece and determine its maker, says Robinson. She once spotted, for instance, an iridescent Loetz piece on a Loetz Facebook fanpage that someone had purchased at Goodwill for $4.99. As a member of this group, I saw the post, reached out to the owner, secured the consignment, and sold the piece for $21,250. With the right training, you could be $20,000 or one chic glass vase richer, but an anonymous piece can be of just as much decorative value. Steuben Glass MCNY/Gottscho-Schleisner//Getty ImagesWorks by Steuben Glass, shown here in the 1930s. Origin: EnglandEra: Early 20th centuryMarks:Potential value: $$One name to prioritize when buying cut glass is Steuben. The company was founded in 1903 by English glass genius Frederick Carder and pieces made during his lifetime can be found at auction houses of all sizes. Not all pieces by Steuben were signed, so best to familiarize yourself with the craftsmanship and style of signed originals. You can start by ordering The Story of Steuben Glass, reproduced in 2021. Auction records also provide invaluable information on current market value and markings. One rose quartz Steuben vase sold at Sothebys in June for $7,200, but smaller, unsigned works can be found for a steal at smaller auction houses or even your local antiques mall.Depression Glass Adrienne Bresnahan//Getty ImagesDepression glass is characterized by bright colors and is easy to find at antiques stores. Origin: United StatesEra: 19201940 Marks: NonePotential value: $During the Great Depression, very few could afford real cut glassworks with carefully etched, hand-done decorations on their surface. Enter Depression glass, a nearly identical style of mass-produced glassware that could be assembled in minutes at interwar factories and sold for a fraction of the real deal. Since it was made in larger quantities, today Depression glass is generally less valuable but still gorgeous and accessible, even more easily online. A key to identifying original Art Decoera pieces is by colorthe more garish the better, as this was the fad at the time. Think acid green, royal blue, and mustard yellow. Also keep an eye out for a telltale seam, usually down the center of the vessel. Lalique Glass Courtesy of Heritage AuctionsLalique Poissons vase, circa 1921. Origin: FranceEra: Early 20th century Marks: Signed Lalique, R. Lalique, and R. Lalique FrancePotential value: $$Also popular during this era was Lalique glass. The French glassmaker was founded in 1888 and is still in operation today. Heritage Auctions set a record for the maker when they sold a bright blue glass Poissons vase for $55,000 last year. Ren Lalique, the companys founder, was known for a softer touch than Steuben and depicted dreamy depictions of birds, dancing figures, and flowers across vases, glass objects, and even hood ornaments. Lalique operated with a high level of quality but was able to produce at a broader scale thanks to innovative production methods.His finishing touchesenamel and frosting in particularhelped distinguish his work and will help you distinguish an original 100 years on. If the bottom of the glass is signed R. Lalique, that indicates the vessel was made before 1945; the initial was dropped after Laliques death that year. Because many early Lalique works were made in large numbers, identification can occasionally be straightforwardif you find a piece out in the world, a simple reverse Google image search will give you a clue. But be forewarned: Lalique glass is catnip for forgers, so consult an expert to confirm its authenticity, should you find a frosted beauty on a thrift store shelf. Tiffany Studios Glass Courtesy of BonhamsTiffany Studios Favrile glass and bronze Wisteria table lamp, 18991918.Origin: United StatesEra:Marks: Potential value: $$$We cant talk about glass without touching on Tiffany Studios, which has been having a renaissance over the past few years. As far as 19th- and 20th-century glass goes Tiffany is likely the most well-established and well-known name in glassmaking, achieving the highest prices at auction and really the only name that could be considered a blue chip commodity, says Ben Walker, Bonhams global head of modern decorative art and design. Robinson, of Heritage Auctions, says the same: Over the past two years, prices for Tiffany Studios glass have remained remarkably robust. She adds that prices for Loetz, a rival of Tiffany known for vibrant, delicately decorated designs, have been gradually increasing, so the maker may be one to watch for new collectors.Tiffany lighting, desk sets, and paperweight vases perform particularly well at auction if you happen to find these out in the world. One Tiffany Studios Dragonfly lamp doubled its estimate, selling for $275,000 in 2022. But before you give up your collecting quest, its important to remember there are still inexpensive buckets within these makers oeuvres. There are numerous Tiffany Studios and Lalique pieces that sell below $1,000 at auction, says Robinson. Fantastic pieces of Victorian era glass and examples by later makers such as Steuben, Loetz, Galle, and Daum are also available to emerging collectors.Murano Glass Courtesy of BonhamsA rare Carlo Scarpa Variegati vase designed for Venini, circa 1942.Origin: Murano, ItalyEra:Marks: Mostly unsignedPotential value: $$$$Murano and Venice have long been centers for Italian glass production. Glassmakers from all over Italy still flock to the islands to train under masters. Venetian glass was a popular collectors item for royalty, aristocracy, and the merchant class from the 16th to 18th centuries. More recently, craftsmen reinvigorated glass production in Murano during the first half of the 20th century. Midcentury and postmodern Murano glass is a great avenue for new collectors. One name that Walker, the specialist at Bonhams, shared with us was Lino Tagliapietra. He is a good example of an artist glassmaker who worked and trained in Venice and brought his knowledge over to U.S., he says. Finnish architect and designer Alvar Aalto, which we tend to think of for his innovation in bentwood, also worked in glass, designing the amoeba-shaped Savoy vase that has regained popularity in recent years. Though still in production, vintage 1960s examples of Murano are available on the secondary market and often identifiable by original stickers or hand-etched signatures that follow the bottom edge of each vase. Paolo Venini and Carlo Scarpa are two Italian legends to keep an eye out for as well.Czech and Bohemian GlassHeritage Images//Getty ImagesA Bohemian sweetmeat dish, circa 1750. Origin: Czech RepublicEra: 16th century through the mid-20th centuryMarks: Various makers marksPotential value: $$Czech glass has also had several heydays, starting with Elizabethan-era production under the patronage of Rudolf II. Bohemian glass of the 1930s is accessible on sites like Etsy and eBay, but youve really got to know what you are looking for. Much Czech glass of this period was unmarked, but the colors of the era are instantly recognizable: soft amber browns, eggplant, hyper greens, and deep reds were popular. Pressed Czech glass from later in the century can be identified by two vertical lines running from the top to bottom of the object, indicating that it was made with a mold. Stanislav Libensky and Jaroslava Brychtova generate some of the highest prices of all the modern glassmakers, says Walker. Petr Horas work, following in the Czech tradition of glassmaking and design, combines bold colors and strong forms. His work would seem undervalued compared to that of Libensky and Brychtovas work.For real Czech-heads theres also Borek Sipek, the lesser known but critically beloved designer known for his extremely wacky and technically impressive designs. Czech glassmaker Lasvit still offers a small selection of new products by the designer. (Fun fact: Their headquarters in Nov Bor, Czech Republic, is covered in glass shingles and sits between two 18th-century buildings that housed glassmakers workshops when they were first built.)