Masking Off
First remove all of the sharp keys from the keyframe and mask off the parts of the sharp keys that will not be painted black. This includes the top surfaces of the sharps themselves. The bone is slightly translucent so we have to keep the tops of the sharps without color. Of course, the bone will be glued to the top/front of the sharp keysticks - another reason to keep this area paint free. The rear half of the keysticks remain unmasked even though they will not be painted.