Clustering of users inputs in multi-user Interactive Evolutionary Computation is intended to allow to collect large data sets for user-behavior modeling, while preserving the user's individuality. By clustering the user input data, we group together similar behaviors and distribute opposite ones, thus preventing conflicts in data resulting from opposite opinions of different users. Without this clustering, it might be not possible to use data obtained from several users for the behavior modeling. This paper tries to present the application of Self-Organizing-Map clustering in the task of font design with Interactive Evolutionary Computation interface.