Surfacing inlays

When running a surfacing bit to surface an inlay, do you run the bit with the grain or across the grain

Along the grain, or at a slight angled offset:


Wood always cuts smoother with the grain. Running across the grain leaves a much more rough surface. The primary reason is across the grain you are cutting the straws of the wood that tend to be unsupported. If you took a bunch of straws and tried to cut them across with a real sharp knife you might get some or all to cut but as you go across the bundle you would more and more ragged cuts because the ones on the outer edges tend not to get support from the other straws like the ones in the middle. With the wood the same thing applies. Cutting with the wood grain can still get tearout but the fibers of the wood support each other better and so you get a smoother cut.