Rift sawn, Quartersawn or plain sawn flooring
Rift Sawing: The most stable boards, and also the most wasteful to produce, are rift sawn planks. Each of these boards is cut radially perpendicular to the growth rings of the tree. There are large triangles of waste left from between each board. As a result, rift sawn lumber is costly to produce and therefore, the most expensive type of planks available from a log. Example of a rift sawn floor.
Quartersawn is the term used to describe the method of sawing the raw oak log at the mill. The log is sawn into quarters and then cut at 45 degrees. The wood cut is made parallel to the wood's medullary rays instead of across, like most lumber is sawn. This type of milling gives you the sought after "ray flake" that is desirable in appearance. This 'ray flake' also known as 'tiger striping' is the visual distinction in quartersawn oak. Cutting oak this way gives incredible stability meaning the flooring is less prone to gapping and warping. A floor with this grain pattern can even look three dimensional. This is one of the most distinctive floors you could ever put in your home. Example of a quartersawn floor.
Plain sawn The most simple method for milling a log into planks, plain sawing, involves making a series of parallel cuts through the log. This method is quick and leaves the least amount of waste. Because of the directional tension across the grain as the wood dries, ages and wears, flat sawn boards are more prone to cupping, gapping and expanding. Plain sawn lumber has a large variety of appearances based on the angle of the growth rings relative to the surface of the board. Often, these rings can be nearly parallel to the board, creating large cathedral patterns. Example of a plain sawn floor.