OBERHOFFER's macroetching agent is a versatile chemical solution used primarily in metallography. It consists of a mixture of aqua bidest, denatured ethanol, hydrochloric acid, ferric chloride, copper dichloride and tin(II) chloride dihydrate. The solution acts on metals and alloys to reveal their microstructural properties. This is achieved by chemical reactions in which the etchant selectively attacks the surface of the metal samples, with iron(III) chloride, copper dichloride and tin(II) chloride dihydrate acting as oxidizing etchants. The hydrochloric acid serves as a strong acid medium, while the ethanol acts as a solubilizer. The aqua bidest provides the solvent for the other components. By applying the solution to metal samples, distinct microstructural differences between different phases or microstructures can be revealed, leading to improved scientific knowledge and engineering analysis.