When looking to purchase an antique stained glass windows there are many thing to consider. One of the main consideration is price. If you are looking to purchase an expensive window, such as a Tiffany, and spend several thousand dollars it is best to get a professional appraisal prior to the purchase.
You should also inspect the window to see if it was repaired. Often times I seen windows that were very poorly repaired. When looking to see if a window has been repaired look at the solder joints. Newer solder joints have a smoother shinier finish. Also look for pieces of that are a different shade than they should be. Often times it is very difficult to match the glass so you have to use something close. When purchasing a window the best advice I can give is to use common sense. The chances of finding a treasure is pretty remote so you should buy it for it's beauty, and by chance it is worth a lot of money that is a bonus.
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Antique Stained Glass Windows
If a Tiffany is out of you price range and you are looking for an older stained glass window, you should consider the following. Be sure to check the window out throughly for structural stability and broken pieces. I've had several people come to my studio with broken stained glass window and were horrified when they found out the price to repair it. Even one or two small breaks can cost over a hundred dollars to repair. You also inspect the window to see if it was repaired.
Stained Glass Directory