A rotary blade sharpness tester is provided. The rotary blade sharpness tester comprises a rotary blade holder, supporting means for supporting a cuttable material, a moving mechanism to cause relative movement between the blade holder and the supporting means, and hence the cuttable material when supported on the supporting means, an activation means to activate a rotary blade held in the rotary blade holder and cause rotation of the blade before the blade comes into contact with the cuttable material. During the relative movement between the blade holder and supporting means the rotary blade movably contacts the material. The sharpness tester further comprises force measuring means operable in use to measure the force of the rotary blade on the cuttable material.