A finished coped joint appears to be a perfect miter, in which the ends of two mating pieces of molding are cut at 45 degrees. In coping, however, only one of the pieces needs to be cut.

Even on perfectly square corners, 45-degree angles won't always yield ... Use a damp (not wet) cloth to remove excess glue ...

Jigs make life so much easier, and when you build one yourself it's even better. Make perfect 45 degree mitered corners every time with this do-it-yourself jig made of plywood. You can build this ...

The cleanest way to do that is cutting 45 degree angles at the end of each board, called a miter cut. Here’s the formula to determine the length each of your boards should be cut. First ...