The circles in old windows, commonly known as a "bullseye," are a byproduct of the historic crown glass manufacturing process. Glassmakers would blow a hollow globe of molten glass, attach it to a spinning rod, and rapidly spin it until centrifugal force flattened it into a wide, circular disk.
Back then one of the most popular ways of making window glass was to spin molten glass into a disc shape. The window panes would then be cut from this disc. But the method wasn't perfect and the centre of the disc would be left with a ripple effect in the middle. This was called the Bullseye.
Here's a simple way to tell: ✅ Check the Etching: Look at the corner of the glass — most windows have a small etched code or logo (like “LoE 2005” or a manufacturer's name and date). That number often tells you the year the glass was made, which is usually the same year the window was installed.
Old glass has ripples because of antiquated manufacturing methods used before the 1950s, specifically crown or cylinder glass blowing techniques, rather than it melting or sagging over time. These methods produced uneven, hand-blown, or spun sheets that resulted in characteristic distortion, bubbles ("seeds"), and wavy lines.
The circular marks on the glass surface are referred to as suction cups or roller marks. These marks may occur on the glass surface as a result of using suction cups to move the glass during the manufacturing process.
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 little dots on your windows—known as frits—are made of baked-on ceramic paint. They protect the window's adhesive seal from UV rays, hide unsightly glue from the outside, prevent the glass from warping under intense heat, and help deter birds from flying into the pane.
Valuable antique glass is typically identified by hand-blown indicators like pontil marks, manufacturer signatures, heavy weight, and rare colors like amethyst or cobalt. Look for signs of age such as unevenness or scuffs on the base, and prioritize pieces in excellent condition without cracks, chips, or cloudiness.
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.
There are no microorganisms on planet Earth that are able to break down glass materials, and since it takes thousands of years, there is not a single glass bottle on the planet that has even gotten close to decomposing. The surface of some glass bottles will absorb moisture, crystallize, and flake off.
Ditching shades has a lot of upsides regardless of who you are. Uncovered windows bring in natural light, boost well-being, and offer a view of the world outside. The trade-off, of course, is that they also put those inside on display to passersby, and in the summer, they channel heat.
In the 1700s, large flat sheets of glass could not yet be efficiently manufactured. Instead, glassmakers created window panes using manual, lung-powered techniques. Artisans melted silica and other materials in wood or coal-fired furnaces, then shaped the glowing, molten "gather" using one of two primary methods before cutting it into smaller panes:
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.
Standard manufacturing of wavy glass for windows was phased out in the mid-1950s.
An old fashioned glass is most commonly called a rocks glass. It is also widely known as a lowball glass (in contrast to a tall highball glass) or simply a whiskey glass.
The value of a stained glass window is determined by factors such as its age, condition, size, artist, and historical significance, with prices ranging from a few hundred to hundreds of thousands of dollars.
Yes, glass absolutely existed during the time of Jesus. In the first century AD, the Roman Empire was undergoing a major technological revolution in glassmaking.
Windows 7, 8, 10, and 11 are different versions of the Microsoft Windows operating system. Windows 7 was released in 2009 and was succeeded by Windows 8 in 2012. Windows 8 was a major departure from previous versions, with a new interface optimized for touch-based devices.
People refuse to update to Windows 11 primarily due to strict hardware requirements that force expensive new PC purchases, a reluctance to give up local accounts for Microsoft accounts, and a desire to avoid bloated AI features. Others simply prefer the familiar interface and stability of Windows 10.
The most sought-after vintage items span several key categories driven by nostalgia, craftsmanship, and rarity. Top-tier collectibles include Mid-Century Modern (MCM) and Art Deco furniture, luxury designer luggage and apparel (e.g., vintage Louis Vuitton trunks), and rare pop culture memorabilia like vintage trading cards and unopened toys.
The customary definition of antique requires that an item should be at least 100 years old and in original condition. (Motor vehicles are an exception to this rule, with some definitions requiring an automobile to be as little as 25 years old to qualify as an antique.)
You've probably walked past these style windows countless times, but have you ever wondered what that thick round circle is? These are known as a bullseye and they're a direct result of how glass was made before modern manufacturing.
When there's a cold snap headed your way, head to your pantry for potatoes. Slice the spud in half and rub the cut end directly on the glass or windshield. The sugars from the potato keep water and ice from adhering, and there's science to back it up, too.