The Bang Sisters are probably or were! the most advanced precipitation mediums that ever lived, their work is famous within the community and the research has shown that the very paintings themselves have a pigment or chemical in them, that can only be found in one thing....that being the silk of a butter fly wing!

You can do this too, with practice and a ton load of patience.  Simply gather paper or card, some pens, pencil anything will do, even a finger nail or leaf...make a stack, pen paper, pen paper etc and fill your box ( or basket ) make sure it is tight and blackout once the lid is on.  Sit back and jut go in too a relaxed state or trance...even play music to the box and in a very short space of time things will start to appear.