Hi mate , thank you .. my backgrounds model painting ( D@D wh40k , 28mm , etc) so im using some old forge world weathering powder that i use on tanks air craft etc ... a little goes a long way ..unfortunatly it was discontinued quite a few yrs ago ,,. You literly use a small brush and brush it on , then add more if you want it darker .... the biggs helmet took about 20 mins .