Here is the take on runout from Hoffman Guitars.
"QUARTER SAWING AND RUNOUT: Both of these factors are a result of the way in which the wood is cut. Quarter sawing means just that -- the log is cut to length (usually blocks of about 24") and then cut (or preferably split) into quarters (called billets), and the boards are then sawn off the resulting flat sides. The result is (hopefully) wood in which the grain lines are vertical to the surface, or close to it. This works better in wood like sitka where the trees are very large and less well in wood like red or Appalachian spruce where the trees now available are often quite small. Runout refers to another form of grain, which must run parallel to the flat plane of the wood. This is best achieved by splitting billets out of the log, rather than cutting them. Both of these conditions are highly desirable, even essential to quality instruments. In brief, they contribute to a high strength to weight ratio. This is important since strength is necessary to resist the pull of the strings and weight (mass) is an "evil" as it will dampen the tone of the instrument. Fortunately, there are now a good number of suppliers who are very knowledgeable about how to cut guitar wood. As a result, the quality available today is the best it has been in my career."
layful:
