Barium sulfate has wide range of applications. It is primarily used in oil well drilling fluid, and as filler in the paint and varnish industry. It is one of the major constituents of the pigment Lithiopone and the white pigment for paints. It improves the resistance against acid and acidity for plastics when employed as filler. Further it is employed as a component in strobe pyrotechnic compositions, and as a coating for photographic papers to improve the effectiveness of the image. Baryta, a thin layer of barium sulfate, is used to make the papers bright for ink-jet printing. In the chemical and pharmaceutical industry, it is used as a catalyst support when selective hydrogenations are required, for e.g. in Rosenmund reduction (Pd on barium sulfate). In colorimetry, barium sulfate is used as a diffuser to measure light sources. In the medical field, barium sulfate suspension is used clinically as a radiocontrast agent for X-ray imaging and other diagnostic procedures. In biomaterials research, it is one of the components utilized in the preparation of acrylic bone cements.