German etched steel casket

The cast iron and steel produced by smelting couldn’t be worked as it is; it had to be rendered ductile. Before the first rolling-mill opened, the various types of iron and steel had to be made by hand, which took a long time. Hammer-forges existed from the 16th century and later cutting-mills were added. Not until much later did iron come on the market that did not need to be laboriously processed.   By the late Middle Ages southern Germany, particularly Nürnberg, had become a centre for decorating iron and steel. Coffrets, caskets and boxes were specially treated to decorate them; they were etched. The plain steel was warmed and coated with etching ground or resist, for instance liquid wax, paraffin, resin or asphalt. Ornamental designs were drawn in this etching ground and then scraped out so that the metal was laid bare in the places where the design was to be. Then the object was framed  in wax and acid was poured in, to etch the exposed metal. As soon as the metal had been ‘bitten’ deeply enough, the rest of the acid was washed off and the piece was dried and cleaned with oil of turpentine.