6.4. Subject-matter group

T 763/89 considered the issues raised by making a selection from a generically defined group of multilayer materials. The patent related to a reversal colour photographic material comprising three layers having differing colour sensitivity, each layer comprising a further three layers having the same colour sensitivity but differing photographic sensitivity. The closest prior art consisted of a reversal material with "at least two" layers. The opponent had argued that the multilayer materials disclosed by this prior art also included the three-layer material claimed, therefore causing lack of novelty. The board, however, held that it was new: although "at least two" was synonymous with a multilayer material and set the lower limit in the form of a double-layer material (the description related to any multilayer material without specifying an upper limit for the number of possible layers), the only theoretical examples given for such multilayer materials were double-layer materials. Nor did the documents cited in support of the opposition as much as hint at a three-layer material. It might appear logical for a three-layer material to form part of the group of multilayer materials in the cited documents, but this did not mean that it was thereby disclosed. On the contrary, it was a new material forming part of this group and selected from it. The board handed down this ruling in the context of previous case law on selection inventions involving chemical substances. This had provided that a technical teaching was prejudicial to novelty if it disclosed a substance in individualised form, i.e. one clearly distinguishable from structurally similar substances. This principle for assessing the novelty of individuals as distinct from a group could be applied to things such as the photographic material in question, which was clearly distinguishable from other things forming part of the same generically described group.