A plytooth saw blade should be used when you need to cut plywood with a minimum of tearing or shearing in the wood. The plywood saw works by cutting the wood with a large number of small teeth. The cutting action with the small teeth should produce a very smoothly edged cut. Saws with fewer or larger teeth may cut quickly, but they will also create a rougher edge.
Plytooth saws are usually mounted as circular blades that cut through plywood quickly and efficiently, while also producing a smooth edge via the action of its many small, sharp teeth. Most plytooth blades are going to be around eleven inches long, and have about fourteen teeth per inch along the blade.