What is a positive picture produced with sensitized collodion on a smooth surface of black varnish, coating a thin plate of iron; also, the process of making such a picture. [Written also melainotype.] called?

melanotype — A positive picture produced with sensitized collodion on a smooth surface of black varnish, coating a thin plate of iron; also, the process of making such a picture. [Written also melainotype.]. (Webster's 1913.)