Abstract: A process of producing a cranial plate duplicating the dimensions of an excised portion of the cranium comprising, obtaining an excised portion of the cranium of a patient, preparing a three-dimensional impression of the excised portion in an impression material, removing the excised portion of the patient's cranium from the impression material to provide a mold cavity, and thereafter filling the cavity with a sterile resinous material which sets, and thereafter removing the set resinous material to form a plate duplicating the dimensions of the excised portion of the patient's cranium, and finally surgically installing the plate in the patient's cranium to replace the excised portion of the cranium earlier removed.