The preparation of wood-plastic combinations can be regarded as a special field of graft-copolymerization. It is therefore quite understandable why this idea was first introduced by graft-copolymerization specialists. On the basis of the theory and technique of radiation-induced graft- copolymerization, which has been greatly developed since 1950, wood-plastic combinations appeared simultaneously in the United States of America and in Europe. As is known, intensive American research on wood-plastic combinations is based on four patents by Kenaga from 1958, which were published in 1963. The worldwide interest in the matter was initiated, however, by Karpov's paper of 1960 based on Soviet patents from 1958 and 1960.