In T 815/93 and T 141/93 the claims comprised both product features and features for a process for manufacturing the product. In both cases, only the process features distinguished the invention from the prior art. Following the case law on the novelty of product-by-process claims, the board found that process features not previously described could establish the novelty of the claimed product only if they caused it to have different properties from the products previously described. Neither the patent proprietor in the first case nor the applicant in the second case could demonstrate this.