is oil that serves as a temporary or permanent component of a manufactured product. Aromatic process oils have good solvency characteristics; their applications include proprietary chemical formulations, ink oils, and extenders in synthetic rubbers. Naphthenic process oils are characterized by low pour points and good solvency properties; their applications include rubber compounding, printing inks, textile conditioning, leather tanning, shoe polish, rustproofing compounds, and dust suppressants. Paraffinic process oils are characterized by low aromatic content and light color; their applications include furniture polishes, ink oils, and proprietary chemical formulations.

Also see proprietary product.