The invention relates to a kit of parts suitable for preparing a cured biocompatible silicone polymer material including an X-ray contrast agent, the kit comprising two or more containers containing a fluid component, which components - when mixed - form a fluid curable biocompatible polymer composition, which upon curing forms the cured biocompatible silicone polymer material, wherein a first container contains a fluid component A, which component A comprises a curable silicone (pre-)polymer and a curing agent and which component A is essentially free of curing catalyst and metallic X-ray contrast agent particles, and a second container contains a fluid component B, which component B is a dispersion comprising metallic X-ray contrast agent particles and which is essentially free of curing agent.
