12.4 Layout Practices Layout must be done with accuracy. Although layout tools can be used many ways, select the tool that is best suited to your work. 12.4.1 Marking Points When marking a distance, the best pencil mark to make is an arrow or V. See Figure 12-28. The point of the arrow shows the proper location. A pencil dot may be lost among the scratches or blemishes in the wood. A short line does not tell which end of the line is the proper measurement. When making the mark, do not press hard. Remember, any pencil marks, dents, or scratches you make during layout must be removed later. Erase all unnecessary pen- cil marks. Be sure that the rule you use is in good shape. The end should not have dents. If a corner is dam- aged, begin measuring from the 10″ mark. For exam- ple, to lay out a distance of 3″, measure from the rule’s 10″ mark to the 13″ mark. Remember to account for starting away from the end of the rule. When using a tape, make a habit of frequently inspecting the hook for damage. If the hook has been bent, your measurements will be incorrect. It is a good practice to have a shop measurement standard, an object of known dimension that can be used to check the accuracy of all tape measures. Select a material that won’t change dimension significantly due to changes in temperature or moisture. For example, solid wood is not a good choice. 12.4.2 Lines Most lines are made using a rule or square. For lines that must be parallel to the edge, use a mark- ing gauge, combination square, or hermaphrodite caliper. 12.4.3 Circles and Arcs Compasses, dividers, and trammel points make accurate circles and arcs. To set them, place one leg on the 1″ or 10 mm mark of a rule. Adjust the other leg according to the desired measurement. Again, be sure to account for starting away from the end of the rule. Arcs are partial circles. The arc has a center point and radius. Set the layout tool for the radius of the arc. Then locate the point of the tool at the arc’s cen- ter and swing the desired arc. 12.4.4 Polygons Common polygons include triangles, squares, rectangles, hexagons, and octagons. Polygon shapes are used for a variety of items including tabletops, mirror and picture frames, and clock faces. Two common tools used to lay out polygons are the framing square and protractor. Set angles on the framing square using two pieces of wood and the measurements on the tongue and body. See Figure 12-29. The Fine Tool Shops Figure 12-27. A profile gauge conforms to the shape of the piece to be copied. Goodheart-Willcox Publisher Figure 12-28. Points are most accurately marked with an arrow or a V. 1 2 3 4 5 160 Section 2 Design and Layout Copyright Goodheart-Willcox Co., Inc.