Using a Straightedge to Draw Accurate Lines

In this three-minute video I demonstrate how to use a few simple techniques to accurately align a straightedge on points so that your line is where you want it to be.

The four steps to draw accurate lines through points:

1. Mark the points where you want them ahead of time. These can also be cross hairs from a compass or pinpricks from a divider or scribe tool.
2. Place the pen or pencil directly on one of the two points. This will act as a pivot point for the straightedge.
3. Pivot the straightedge against the pen or pencil, and align it to the other point. The alignment has to be shifted rather than directly centered on the point because the pen or pencil has a diameter, as seen in the video.
4. Check alignment of the second point with your pen or pencil. If all is good, draw your line. It should cross through the middle of your points.

The Fatness of Your Tool

Drawing tools such as pens, pencils and markers have diameters to them that make alignment difficult when using a straightedge. In this picture you can see what is going on. You need to use your alignment skills to overcome the offset of your tool in order to get your desired result. Notice that many markers have such thick housings that the center line is far off from the straightedge.

You can angle your pencil to get a better fit, but it still will have a small offset from the straightedge.