The reference grid of baseline, centreline, waterlines, buttock lines, and stations are laid out with care to ensure squareness. For each profile, points will be marked as per positions on the table of offsets or as scaled from the lines plan. In the case of a lines plan, points will be read off both relevant views (i.e., a station will have heights above the baseline from the body plan view, and distances from centreline from the plan view). Small nails are located at the marked points, allowing a flexible batten to be drawn against them. Tracing along the batten gives the shape of the profile.