There are two common methods for mounting a canvas print. You can get it stretched over wooden bars or have it glued directly onto board.
Stretching the canvas onto bars gives your print a deeper profile; often about an inch thick. This method generally suits single, thin frames which wrap nicely around the edges.
Mounting the canvas onto a board gives a much more shallow profile; roughly 3mm deep. This method lends itself to more traditional and prominent frames. You can even layer frames on top of each other to really make a statement. More on that later.