This work centers on the optimization of the surface of glass fabrics and mica paper. Mica paper and glass fabrics are important materials for insulation tapes. Insulation tapes are used as main insulations for stator bars used in generators. For surface optimization of glass cloth and mica paper with an epoxy coating cationic-photopolymerizable resin systems are used. These consist of one out of three epoxy resins and a photoinitiator. The epoxy-modified siloxanes are used as silane coupling agents. These improve the adhesion between the surface of the modified materials and an adhesive that joins the individual glass fiber and mica paper layers together. For the determination of the ideal recipe different experiments were carried out. The kinetics of the cationic curing reaction of the epoxy components was determined to select the most suitable epoxy for further experiments. In addition, various properties of the epoxies were assayed, for example their storage stability was determined and their viscosities were optimized. The distribution of the epoxy coating on the surface of the materials was observed with a scanning electron microscope. The dielectric loss factor of the modified materials was measured to check the electrical characteristics and the compatibility between the modified materials and the adhesive or the binder resin. By comparison with a standard product the materials are further improved.