Jax Metal Finishing Solution, Pewter Black, 4 oz.Produces a dark, black antique finish on pewter, lead, brass, bronze, copper, nickel, tin-lead alloys and solders. Perfect for projects involving different types (or unknown types) of metal..
you can not use a brass or copper or any other metal finish on pewter you have to use the solution made for that metal
for my last project I used a product from Bluejacket Ship Crafters called pewter black, it appears to be a private labeled product but maybe the same as pewter black, I applied it twice and obtained a color I was happy with, not jet black but a very deep dark grey, further coats may have produced a truly black color but I was happy with the color I ended with. I followed the directions and coated with lacquer so far no rub off I did it April of this year,