Quarter Sawn vs Rift Sawn vs Flat Sawn Explained

They say Quarter sawn lumber has a grain angle off the face of the board of 90 to 60 degrees. Rift sawn lumber has a grain angle off the face of between 60 and 30 degrees with 45 degrees as the optimum. Flat sawn is the most common lumber and has the highest yield from the log.
00:00 Introduction
00:35 Flat sawn or Plain sawn
02:48 Quarter Sawn
05:20 Rift Sawn
05:58 Final comments