GROESBECK's macroetching agent, consisting of Aqua bidest, sodium hydroxide and potassium permanganate, is well known for its use in metallography, especially in the examination of high-alloy steels and cast materials. Sodium hydroxide and potassium permanganate, as a strong alkali and strong oxidizing agent, when combined with water, produce a corrosive solution that selectively acts on specific microstructures in metals. In this way, differences in the metal structure are highlighted and made more easily visible. The resulting color contrasts improve the visual distinguishability of metal components and enable more precise analysis. By using this solution, therefore, profound insights can be gained into the nature and properties of the analyzed materials.