A chambered doctor blade assembly which can be placed against a roller of an inking unit of a printing machine, in particular onto an engraved roller, has a chamber connected to the surface of the roller by means of an orifice through which printing ink can flow. The method comprises prefabricating the stone into slabs at or near the location where it is quarried, into sizes and shapes which are common, and often standard, in household bathrooms and kitchens. The hafnium sequence uses HfCl4 and water vapor.