We've got two different black/gold looks in M3. This is the heavier/more expensive of the two. Black Bronze is made by combining white bronze powder and graphite, resulting in a metallic black that is gorgeous. The gold portion of this blank is made with brass powder and gold pigment. LOTS of metal in this one, making for a very solid feeling finished product whether it's a pen or jewelry.
Please note: All of our M3 blanks are square at this time. We're still working on getting the rods perfected with the new urethane based material.
While we recommend the M3 polish, you can sand and polish using the same methods you'd use for resin blanks. Our M3 polish is a metal polish specifically tested for use on our material and we know it provides amazing results.