An Etymological Dictionary of the German Language/Annotated/Blech
Blech, neuter, ‘thin metal plate, tin plate,’ from the equivalent Middle High German blëch, Old High German blëh, neuter; it corresponds to Old Icelandic blik, neuter, ‘gold, thin plate of gold.’ In English the word is not to be met with; it is formed by gradation from the root blik, which appears in bleichen, and means ‘shining.’ —