Details materials for liquid penetrant inspection of metal and non-porous, non-metal parts for material discontinuities open to the surface providing systems required by MIL-STD-6866 and MIL-STD-271(SH). Coverage includes classification, applicable documents, materials, qualification, developers, solvent removers, toxicity, corrosive properties, flash point, viscosity, water tolerance, storage temperature stability, and penetrant contamination.