Cosmoline

Cosmoline is the genericized trademark for a common class of brown, wax-like petroleum-based corrosion inhibitors, typically conforming to United States Military Standard MIL-C-11796C Class 3. They are viscous when freshly applied, have a slight fluorescence, and solidify over time with exposure to air. The main ingredient in cosmoline is aliphatic petroleum solvent, which is volatile and evaporates over time.