Wavy glass is a type of historic, mouth-blown or machine-drawn glass characterized by ripple-like surface imperfections. Instead of perfectly flat surfaces, it causes subtle visual distortion and bends light. Common in homes built before the mid-20th century, it is also highly sought after in modern design.
Standard manufacturing of wavy glass for windows was phased out in the mid-1950s.
The wavy look comes from how glass used to be made. Back in the day—like before the early 1900s—glass wasn't made the way it is today. Instead of being poured and perfectly flattened, it was blown or drawn into sheets. These sheets were then cut down and used for windows, but the process left imperfections.
Wavy glass with visible distortions is most commonly called restoration glass, antique glass, or rippled glass. This characteristic look is a byproduct of older glassmaking methods used between the 1700s and early 1900s.
To determine if your vintage glassware is valuable, look for signature brand markings, unique colors (like uranium green or cranberry pink), and intricate textures or etchings. Many everyday pieces from the 1920s–1960s are worth money if they are from highly collected makers.
Many everyday vintage "knick knacks" are highly sought after by collectors and can be worth significant money. Look for mid-century figurines, antique crystal glassware, sterling silver objects, and rare nostalgic toys. Condition, rarity, and maker markings are the biggest factors in determining an item's true value.
Twenty-year-old windows are often nearing the end of their typical 15–25 year lifespan and, while they may still function, they are likely less energy-efficient than modern alternatives. If they are wood-framed, vinyl, or showing signs of damage, upgrading usually offers significant benefits in energy savings, comfort, and noise reduction.
The process of creating the initial cylinder, and then reheating a portion of that glass tube cause waves to form in the glass as it may not have heated evenly, or the heat caused bubbles or ridges in the glass. So, wavy glass isn't a product of time or the elements, the glass doesn't sag, it was just made that way.
There are four main types or strengths of glass:
To date glass, examine its manufacturing method, mold seams, and maker's marks. Look for rough pontil scars on the bottom, which indicate pre-1860 hand-blown glass. Modern mass-produced glass made after 1910 will feature smooth finishes and mold seams that run all the way over the lip.
Typical frames were both in iron and wood arranged with one or two sash that opened outwards on hinges attached to the jambs. Glazing for these windows consisted of small rectangular or diamond-shaped panes held in the sash frames by lead cames or wood muntins and reinforced with wood bars.
Rippled glass refers to textured glass with marked surface waves. Louis Comfort Tiffany made use of such textured glass to represent, for example, water or leaf veins. The texture is created during the glass sheet-forming process.
Both types of glass are straightforward to cut, but wavy glass can be slightly thicker. The stakes are higher with wavy glass since it is irreplaceable. So, keep that in mind while you are learning. Line up two of the straight edges of glass about 1/16″ from the edges of two adjacent muntins.
1930s style homes often took inspiration from the Art Deco movement, with curved bay windows a prominent feature in many houses of the time. Architects also looked back through history for inspiration, with many 1930s houses featuring mock Tudor timbered sections and Neo-Georgian sash windows.
To determine if a glass item is a true antique—generally classified as being at least 100 years old—inspect it for handmade characteristics, wear patterns, and manufacturing marks. Authentic antiques will often feel heavier, show tiny surface imperfections, and lack the perfect uniformity of modern machine-made glass.
Wavy glass is still made today by artisans; modern versions of wavy glass still provide the same wavy look but using more modern glass drawing techniques.
Antique stained glass windows typically range in value from $𝟑𝟎𝟎 to $𝟑,𝟎𝟎𝟎 for residential salvaged pieces, and between $𝟏𝟎,𝟎𝟎𝟎 and $𝟏𝟎𝟎,𝟎𝟎𝟎+ for large church windows, historical pieces, or signed works by famous makers like Tiffany.
The cheapest time of year to replace windows is during the off-season, which runs from late fall through winter. Demand drops significantly during these months, prompting manufacturers and contractors to offer steep discounts and special promotions to keep their crews busy.
Andersen® products can be used in any type of project, including new construction, remodel/renovation, and replacement. Renewal by Andersen® products are replacement only. They are specially designed and custom manufactured to fit the existing openings in a home.
The most in-demand collectibles right now include vintage pop-culture memorabilia, rare U.S. currency, classic timepieces, and Trading Card Games (TCGs)—with Pokémon and crossover sets like Magic: The Gathering leading the pack.
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2026 marks the 250th anniversary of the United States, and demand for patriotic material shows no signs of slowing. Antique and vintage American flags, eagles, folk art, and historically inspired decor will remain highly desirable as collectors and homeowners lean into Americana.