An Etymological Dictionary of the German Language/Blech
Blech, n., ‘thin metal plate, tin plate,’ from the equiv. MidHG. blëch, OHG. blëh, n.; it corresponds to OIc. blik, n., ‘gold, thin plate of gold.’ In Eng. the word is not to be met with; it is formed by gradation from the root blik, which appears in bleichen, and means ‘shining.’ —