To arrive at a final judgment about the long-term effects of gamma radiation on paper, five different sorts of paper have been investigated. By way of comparison the influence of an ethylene oxide treatment has also been investigated. The paper types have been chosen in such a way that they are representative of the composition of an archive in the Netherlands. For such a research one has to rely on new paper. However, to get an indication of the effects on old paper, the General State Archives in the Hague has provided a quantity of paper which is roughly 100 years old. To get a picture of aging during a longer period the papers to be investigated were aged for three, six, 12, and 24 days with two different aging methods. In this way insight has been gained into the steepness of the aging graphs and into the effect of the two methods upon the aging process. The results of the physical investigations (folding endurance, bursting strength, and tearing strength) show similarity. The aging process develops in the same way, both with the wet and the dry aging, but this process is faster with the dry than with the wet aging. In the first stages of aging a relatively fast degradation occurs, expressing itself in a steep curve. After the first three days of the aging process, the curve levels off and the decay is slower. -- AATA