Degreased, Degreasing. Removal of grease from a metal surface. This is performed with one of two types of compounds: alkaline or organic grease-dissolving agents. Metal should be grease free for most metalworking operations but can become spattered during production or trimming. Degreasing is accomplished with acetone, detergent or solvent. Splattered grease on the face of a die – or on a blank – will cause a wavy pattern on a struck piece (see photo). Before any finishing or patina operations can be performed, all grease must be removed or streaks will appear in the ultimate finish. Grease on a lacquered medal, however, may be wiped off with a rag.