For optimization of the performance of the protective coatings there is necessary to optimize the following materials parameters: the elastic modulus, hardness, surface strength, film fracture toughness, impact resistance and film-substrate adhesion. Elastic contact between brittle film and indenting particles may lead to the formation of Hertzian cone cracks. These stresses arise from the radial tensile stresses around the contact area. The resulting strain is difficult to be relaxed and it builds up with increasing film thickness. When the elastic recovery force of the film exceeds a critical value, the stresses in the film are relaxed by cracking or wrinkling resulting in delamination.