Abstract: The present invention relates to a method and an apparatus for coating large area solid substrates with metal based alloys or compounds by contacting the substrate surface with an unoxidised metal powders formed by in situ reaction of a metal halide and a reducing agent. The method is suitable for coating large area substrates such as flakes, powder, beads, and fibres with metal based alloys or compounds starting from low-cost chemicals such as metal chlorides. The method is particularly suited for production of substrates coated with metals, alloys and compounds based on Zn, Sn, Ag, Co, V, Ni, Cr, Fe, Cu, Pt, Pd, Ta, Nb, Rh, Ru, Mo, Os, Re and W.