There are rules for making raised paneling, followed from Maine to Georgia in the 18th century. The thumbnail bead is 1/2" wide. From the face surface to the beginning of the plough is 7/16". The plough is 3/16" wide and 1/2" deep. Then, the thickness in back of that varies depending on what your making. As you will see the raised panel feathers down to 1/16" - 3/32". These dimensions are virtually universal up to the Federal Period when things begin to change. >