I prefer a frame with a reveal, where the frame doesn't overlap the front of the painting. This allows the full painting to be seen. It's a fairly modern approach to framing a piece and with the right kind of frame can look fantastic.
This question has come up most recently with the new small paintings. Below are some photos of a few of them in two different kinds of frames. The paintings are mounted with an appropriate glue to matt board or foam core and the board is them placed in the frame. Thanks go to my friend Shawn Kenney for sorting this out.
A small painting can look especially good with a large simple frame. Black can be a bit heavy for some decors, but suits some paintings.


Here you can see the spacing around the piece and how it fits in the frame. For these pieces, there is a 1/2 inch reveal.

Not every piece looks it's best in a black frame and not everyone likes a frame that heavy. The warmth of the wood works brings out the warmth in the painting of the bananas.


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