Grain Direction You can use your fingernail against the wood to determine the direction of the grain, if your nail catches, you know that you are moving against the grain so you should plane the other way, with the grain.

Before cutting a piece of wood, we need to try to determine the direction of the grain, or in other words, the way the fibres are lying in the wood, so we can cut 'with the grain'. In many woods, any attempt to cut against the grain will result in tear-out (photo 1).

Understanding grain direction is key to getting clean, tearout free cuts. On almost any tool — including power jointers, planers, routers, chisels, and hand planes — cutting against the grain can lift and rip fibers instead of cutting them (a.k.a. tearout). Hence the general rule of thumb: Always cut with the grain.