A metal substrate having a uniform textured surface with a plurality of indentations with a diameter in the nanometre and micrometre range is produced by exposure to an etching fluid comprising a hydrohalic acid and a mixture of a hydrohalic acid and an oxyacid, a chloride containing compound, and an oxidant. The etching solution can be used at ambient temperature. This textured surface enhances adherence of coatings or cells onto the textured surface, improves the retention of proteins on the surface, and encourages bone in-growth.