The acidity of wood pulp paper leaves it open to the attack of microorganisms. Neutral paper which has been stored in proximity to acid materials may suffer as well. Disadvantages of using aggressive chemicals are given. Gamma-and X-radiation confer no lasting protection. Mr. F.J. Knubben, former restorer of the Wallraf-Richartz Museum, Cologne, has developed a system in which a non-aggressive buffer solution is applied as a fine spray. The paper is then exposed to UV radiation and a low dose of active oxygen to kill microorganisms and to bleach. Finally, pyroxidine hydrochloride is used to prevent further infestation by microorganisms. The paper stays essentially dry throughout the process. Other benefits are given. Paper previously treated with chlorine can undergo the above treatment after the chlorine has been extracted. Gives tips on mounting, storage, framing, exhibition and environmental control.