Marking knives: a cut above pencils

I use a sharp pencil in the shop to mark crosscuts, mortise-and-tenon layouts, and dovetails. I see a big deal being made about marking gauges and small knives to mark the cuts and layouts. Why are these better? If I make a mistake, I can erase the pencil lines.
—Mike Jory, Castro Valley, Calif.

Marc Adams often hears this question from students at his woodworking school (marcadams.com). His reply: "A knife or marking gauge is a great way to get a precise line that your chisel can reference for a cut. Also, an accurately knifed layout line will help the saw blade track better. Because scribe lines can be difficult to see, I often use a very sharp pencil to darken them in. And remember, some people like to see just a hint of a knife line to prove that the joint was hand-cut."

True, scribe lines can't be erased with a pencil. So follow the measure-twice-cut-once rule when laying out your cuts. If there's any doubt, make shallow score marks to start. You always can go back and sand them off if you've erred or deepen them, if necessary, before making your cuts.