What paint did you use for that metallic finish?

Final paint is a light dusting of Alclad 2 lacquer (airframe aluminum color) over glossy black Krylon base. You can see the difference between just black and black + Alclad in the two smaller photos.

The key here is to have a very smooth object prior to painting. Lacquers are unforgiving and show every little missed part of your surface prep.

* All of the 3D elements for Frostmourne were created by Vertvixen.