A mixture of polymer and inorganic antimicrobial agent (Ia) are provided in a surface layer (A) on at least one side of a polymer support layer (B). An antimicrobial plate or panel or a similar product such as a tile comprises a polymer base material and an inorganic antimicrobial additive which is preferably silver-based. The base material is present in a layer or body supporting at least one antimicrobial surface layer with a thickness which is significantly less than that of the support layer or body. The antimicrobial layer comprises the base material and antimicrobial additive. Independent claims are also included for the following: (A) Preparation of the plate by coextrusion, the support layer comprising a thermoplastic material； (B) Medical plate, especially a tile, prepared by this method and having a thickness of 0.5-5 mm and containing 0.1-0.3% active agent in the antimicrobial layer； (C) Sanitary panel, especially a tile, prepared by this method and having a thickness of 2-5 mm and containing 0.1-0.6% active agent in the antimicrobial layer； (D) Panel for outdoor use, especially a tile, prepared by this method and having a thickness of 15-35 mm and containing 0.3-5% active agent in the antimicrobial layer； and (E) Blister and instrument packaging material prepared by this method and having a thickness of 0.1-1 mm and containing 0.1-0.3% active agent in the antimicrobial layer.
