Thickness. The thickness of paneling varies. In general, plywood and most hardwood paneling is 1/2- or 3/4-inch thick. Other thickness are slightly different, measuring 11/16, 9/16 or 5/8 inch thick.MDF is usually the thinnest paneling available, about 1/4-inch thick. Thicker hardwood panelings that are more than 1 inch thick are also available.owever, if you are covering an existing wall with paneling, thinner panels are best. Measure the thickness of the door, window, base and other moldings in the room. Paneling that is thicker than these moldings will look awkward.