Copper salts, borax and boric acid individually provide good to excellent protection to wood against fungal and insect attack. A new formulation has been developed at the Forest Research Institute, Chittagong, Bangladesh with borax, boric acid and copper sulphate (BBC) in mixture. Immediate precipitation of copper borate occurs when borax is added to a clear solution of copper sulphate and boric acid in mixture. The precipitate dissolves in ammonium hydroxide and an intense blue solution is obtained. On vaporization of ammonia from the solution copper borate is reprecipitated.