AbstractMethods for estimating coating weights on tinplate by removing the tin coating quantitatively were critically examined. The action of several stripping reagents on both hot‐dipped and electrolytic tinplates was studied by measuring weight losses after various periods of immersion and by metallographic examinations of the stripped specimens. Hydrochloric acid inhibited with antimony trichloride was the only reagent which completely removed the tin coating and the alloy layer from hot‐dipped plates and this reagent is recommended for determining total coating weights on hot‐dipped and electrolytic plates. Alkaline potassium iodate is a satisfactory alternative reagent for electrolytic plates. Coating weights determined with these two reagents agreed closely with those determined by iodimetric titrations of tinplate digests provided the latter results were corrected for iodine consumption by the baseplate. Plumbite and bismuthate stripping reagents were found to be unsatisfactory.