First, a sample of PS white oak, the most common and cheapest cut (where the board face is parallel to a tangent of the log round):
Here is a sample of PS red oak:
Next, a sample of QS white oak (where the board face is along a radius of the log):
Here is the QS cut in red oak:
Here is today's subject, a RS sample in white oak that comes from a board that is somewhere between the two cuts above:
A RS red oak sample:
You can see at a glance that the RS wood has a quieter grain with the vertical lines of those annual rings lining up just so without the medullary ray flecks that the QS wood displays. I think this makes rift sawn oak easier to work into a design than either of the other two cuts. And not only for the frame in frame and panel work; see how well mannered it is as panel too:
In any case, if you pay attention to grain patterning in your work, the results will be visually more pleasing and you will find yourself searching for RS wood. This is why we have our red and white oak inventory segregated by cut.