Three main factors determine the cost and quality of frames: Joinery, finishing and material. Don't be fooled by terms like museum quality, custom, or gold leaf. Anyone can use these terms.
Joinery: The best frames have what are called "closed corners". That means the frame is constructed first, then the finishing is done. You should not be able to see the mitered joint. The best frames are built like fine furniture, with corners joined by splines, mortise and tenon, or recessed dowels or screws.
Mid-quality frames often have stapled corners, and then they are finished like the better frames. These look great, and are used most frequently. But over decades, or with handling, the corners may separate slightly.
Lower quality joinery techniques include what is called "chop". The framer purchases prefinished moulding (some of it is truly high quality), cuts it, glues and staples the frame together. The better framers will fill the mitered corners to create the illusion of a closed corner. Chop frames can get very expensive, but they have the advantage of being very stylish and individualized to your décor.
Perhaps the worst joinery has a little plastic plug that straddles the mitered corner. This is not a very stable corner.
Finishing: The best wood finishes are done in many stages, just like fine furniture. Gold finishes also involve several steps. But what you need to be aware of are the different definitions of gold: The best gold finish is genuine gold leaf, up to 24kt. It may be applied smoothly, or it may be antiqued. It is expensive and time consuming to apply well. It is gorgeous.
Mid- to lower-mid quality frames usually use what is called "gold paint leaf", often shortened to just gold leaf. If it doesn't have karats it is not the real thing. Gold paint leaf is an acceptable finish. It can look fine. Just don't be deceived about what you are getting.
Lowest quality finishing generally lacks luster and depth.
Materials: Again, fine furniture construction applies. Quality hardwoods last longest. But softwood pine and barn wood have their place for rustic paintings. The artist may know in what country the frame is assembled, but will rarely know where the wood originated or under what conditions it was milled and finished.
Manufactured wood is turning up, mostly in low quality frames and moulding. And then there is plastic.? It doesn't bear discussion.
I would say, "You get what you pay for" in frames, but it is just not true. Mid-quality and chop frames can command very high prices. It is up to you to understand the quality possibilities and realities. Ask your artist about the frames he/she uses, and understand that artists have to choose their line of frames based on what their collectors are willing to pay. If you want a Cadillac frame you may have to buy it later.
In my next Blog you'll get links showing you how the best framers actually make and finish frames, and inside scoop from an anonymous framer.