The Otto straight cutting shear is listed with a convex, hollow-ground blade. Blade shape is one part of tool selection; compare the exact model and the cutting technique you use.
Match the blade to the task
Use straight cutting shears to establish shape and length. Choose toothed thinning shears for blending or the guarded razor for a distinct texturizing action. Ask a qualified shear sharpener to preserve the original blade geometry when servicing your cutting shear.