When you compare them side by side, antique glass looks a lot different from modern glass, which has everything to do with differences in manufacturing. Since modern glass is not made the same as the original glass found in homes 100-years-old or older, it can be difficult to restore built-ins and make them appear authentic. Fortunately, you can have glass made custom so that it will match the antique glass already found in the home, which often has a bubbled or wavy appearance. Following are the three main types of glass that you will find in historic homes.
Crown glass is identifiable by the curved waves that appear across the surface of the glass. Crown glass also has tiny bubbles called seeds as well as other defects and imperfections. The characteristics of crown glass are a direct result of the manufacturing process. Crown glass is a type of blown glass where the glass blower spins a piece of glass until it resembles a large, thin disc of glass. The glass was then cut to size for use in windows and cabinetry.
Another type of glass made into the mid 1900s, is cylinder glass. This type of glass also has bubbles and imperfections as well as waves. However, the waves on this type of glass makes it look fluid or as if it is melting. Cylinder glass was made by blowing glass into a large cylinder. The glass was then cut down the entire length of the cylinder and placed into an oven so the glass could uncurl and flatten. This method made it possible to create larger panes of glass, but not as large as we are used to today.
Since it was difficult to create large, continuous pieces of glass, ornamental glass was often used in large windows and build-ins. Ornamental glass was created by taking several small cut pieces of glass and joining them together with lead. Ornamental windows were often stained or patterned with etching.
When restoring a built-in cabinet in a historic home, it's vital that you match new glass to the existing antique glass that's already in place. If you don't, the new panes will stand out like a sore thumb. To get the right look, it's often necessary to have the glass maker come to your home to take measurements and get a sample of the existing glass. It's a process, but well worth it in the end.