In toolmaking, so-called ¿rapid tooling¿ offers the possibility for the rapid production of tools and molds for small series and prototypes while reducing costs and delivery times. Compared to conventional materials, additively manufactured tools have some disadvantages which can be compensated by the addition of fillers. In this work, photochemical reactions were used to create an acrylate-epoxy based high temperature resistant interpenetrating network (IPN) and fillers were added to increase the thermal conductivity of the system to print a mold for tin casting. Of six different fillers, the effect on viscosity and penetration depth was determined as a function of the concentrations to determine processability in additive manufacturing (AM). Test specimens were printed on two different printing systems to determine the printing parameters and then subjected to dynamic mechanical analysis (DMA) to determine the glass transition temperature (Tg) and storage modulus (E¿). For selected systems, thermal diffusivities were determined by laser flash analysis (LFA) and thermal conductivities were calculated using densities and specific heat capacities. Finally, two-part molds were printed and several casting tests were performed, measuring the temperature of the metal during the cooling process. Of the three systems (20 vol.% boron nitride, 2,5 vol.% graphene and unfilled), the thermal conductivity of the graphene systems was only slightly higher than that of the unfilled system, but still possessed significantly shorter cooling times. The experiments showed that graphene-filled systems are more difficult to process due to their low curing depth, making them unsuitable for conventional 3D printers. The boron nitride system performed best, possessing about four times the thermal conductivity of the unfilled system and cooling about three to four times faster during the casting tests. In addition, the boron nitride system also exhibited very high curing depths at low exposure times, which should make it processable on most printer systems.