Abstract: A method of laser marking ceramic materials, glazes, glass ceramics and glasses of any desired form, which comprises applying to the material to be marked a 100 to 10,000 .ANG. thick transparent layer of titanium dioxide, then irradiating said oxide layer with a pulsed laser such that the radiation is directed onto said layer in accordance with the form of the marking to be applied, and using laser light of a wavelength which is sufficiently absorbed by the oxide layer, so that a discolouration of said oxide layer is produced at the irradiated areas.

Abstract: A method of laser marking ceramic materials, glazes, glass ceramics and glasses that contain at least one radiation-sensitive additive, utilizing a laser beam as radiation energy source which is either applied to, or focused on, the surface of the material to be marked in accordance with the form of the graphic symbols to be reproduced, such that a change in color is induced at the irradiated areas, wherein the wavelength of said laser beam used as energy source is in the near UV and/or visible range and/or infra-red range, and the radiation-sensitive additive is an inorganic pigment.

Abstract: Process for mass coloring high molecular weight organic material, which comprises using a compound of the general formula (I)(Bi,A)(V,D)O.sub.4 (I)in a tetragonal, scheelitelike crystal structure, in which A is an alkaline earth metal, Zn or a mixture thereof, D is Mo, W or a mixture thereof, and the molar ratios A:Bi and D:V are between 0.1 and 0.4 and 0 and 0.4 respectively.Processes for preparing the compounds of the formula (I) are likewise described.