AbstractThe quality of electro‐tinned coatings (8 02. per basis bos) from the alkaline and acid baths, on steel, has been determined by means of the thiocyanate test, humidity chamber test and visual appearance after the following pre‐plating treatments : pickling in various acid baths, anodic etching in sulphuric acid, and anodic p.ickling in inhibited sulphuric acid. Coatings of equal1 high quallty can be deposited from cithcr bath, but the deposit {om the alkaline bath is less sensitive to pickling procedure than IS that from the acld bath. The best prc‐treatment for alkaline bath deposits is pickling in inhibited sulphuric acid, and for acid bath deposits 1s anodic etching in sulphuric acid. Pickling in hydrochloric acld cads to coatings of slightly lower quality, but is equally effective with alkaline and acid bath dcposits'and there is no deterioration on prolonging the pickling time up to 5 mi