With crown, you don't need to make a line across the entire piece. A little mark on the edge
is enough to show you where to place your saw blade.
A utility knife's usefulness as a marking tool is not just confined to dark wood; it's also the best way to mark the outlines of the mortises for door hinges, lock strikes, and latch faceplates. Because its blade cuts into the wood, you can feel exactly where to rest the edge of your chisel when you start carving out the mortise.