Ready-to-use solution Tartaric acid 2 % for use in histology and/or cytology for differentiation/pickling and blueing. As etchant for Mg-Al, Mg-Mn, Mg-Mn-Al-Zn - alloys and steels in metallography. Etch between 10s and 20 min, only polish dry, then wash with ethanol and dry in cold air stream. Shows grain size in castings, flow lines, also for rolled, forged and pressed samples.