A coped joint is the most elegant and durable way to join interior trim at a room's inside corners. One piece of trim is cut square and meets the corner while the other is cut to meet the profile of the first.
To make the joint, I first miter the correct end of a piece of trim stock to expose the profile as below.
I use a coping saw (the tool in the picture above) to saw away the majority of the waste. This operation need not be exact. Rather, I aim to leave 1/16th of an inch and use an assortment of files to perfect the profile.
This is how the joint meets up:
Here is another example of a coped joint. Here I am installing picture molding, an old style of crown molding and the profile is more complex.
|cut the miter|
|the profile is revealed|
|cut away the waste|
|it's helpful to check the joint's fit on a scrap|