Why only use a Certified Sharpener to avoid incorrect sharpening

What happens when a shear is sharpened incorrectly?

  •  Incorrect sharpening will greatly reduce life and cutting ability of the shear
  •  Can put wrong angle and edge on the blade
  •  Take too much metal off
  •  Ruin shear more than it was already damaged
  •  Leave split ends
  •  Crush hair cuticle instead of slicing through hair and not providing a clean cut

incorrect sharpening image