“Smaller is stronger” is a paradigm in materials development.[1] In the case of metallic materials, the smaller the crystals which make up the material, the more obstacles there are to plastic deformation due to dislocation motion. The utmost limit is found in bulk metallic glasses, which have strengths of up to E/40 (E being the elastic modulus), closer than any other bulk material to the theoretical strength, given by≈ E/20.[2] In ceramic polycrystals, dislocation motion is impeded at ambient temperature, and the strength is controlled by the dimensions of the critical defects. Assuming a semi-circular surface flaw of diameter d, the strength is given by σ π