saw teeth; sharp; razor; Escher; 2D; 3D; old; new; band saw blade

Blue Fier “Escher Teeth” 06/10/19
I was on a tour in an old sawmill in Oregon. These two guys were machining the shape and sharping the band saw that makes the first cuts on a log. The sharpness was being milled by precision tools from precision men. The sawyer could make or break a lumber mill by how he cuts up logs.
The band saw room had ancient saw blades, and this new one being fabricated before me. The Escher-like set of images of teeth and what else do you see? Depending on your angle of view will change your image. The slight triangle in the middle of the curve directed where the sawdust will go.
A craft itself, making and maintaining saw blades for their lumber mill.
The cuts on logs are aided by a laser beam. I had the saw guys place the new one on top of the old saws for contrast. The glaring highlights are from the overhead bare-bulb fluorescents.