Most ready-made frames for oil paintings can be found in the painting or hobby section of a store. Sizes start at 5x7 inches. Most stores carry a good variety of frame styles and colors in a 5x7 frame. If a size smaller than 5x7 is needed, there is an alternative.
Frames intended for photographs can also be used. These frames are very similar to oil painting frames. The only real differences are the depth of the picture frame and the backing and glass included. As long as the frame depth will fit the canvas, the picture frame can be an option. In fact, ready-made picture frames may even be cheaper than those made for paintings.
If you use a picture frame instead of an oil painting frame, do not place the glass in front of the painting. Glass in front of a painting can lead to moisture build up.
Most hobby stores carry medium-size ready-made frames starting at 8x10 and as large as 20x24. As with all frames, they will fit canvases with the same width and height measurements. Paintings easily fit into these frames in either a vertical of horizontal direction.
Medium oil painting frames generally have a good selection of colors and styles to choose from. These frames will cost around 20 to 40 dollars.
Large frames are harder to find in a hobby store, and generally they come only in 20x36 and very basic styles. Many times an artist will have to paint the frame or use a simple woodgrain frame for canvases this size. These frames can be costly, but they can add a touch of class to a large oil painting.
No matter how hard an artist tries, there are times a custom frame may have to be purchased. There are many local stores that sell custom frames, but you should be prepared to pay a hefty price.
When purchasing a ready-made frame, it is a good idea to take the artwork to the store. This will ensure that the frame that is purchased will enhance the subject matter of the painting. If one local store doesn't carry the right frame for the painting, don't hesitate to try another local store or an online store.