Striking lines parallel with the edge of your stock couldn't be easier, once you have a Tooltekt®  Precision T-Square in your shop. The beam has a lip that rests on the top surface of your stock, preventing the tool from rolling like many T-squares. Just drop in the point of a mechanical pencil and scribe a perfectly parallel line by holding the pencil in one hand and sliding the T-square with the other. In addition to the scribing guides, there are 1/4"' diameter holes on 1" centers, ideal for laying out shelf pins.