I love this look!
The base is a shade of blue (will add the name later) by Sally Hansen and Katy Perry's black crackle nail polish on top. This worked out great for me the 1st time, but seems as though the crakle polish was very thick on the 2nd use?! Almost too think to use! I will try this look again but with a new bottle of crackle polish.
BTW the Sally Hansen line of Crackle nail polish did NOT work... well, I will speak for the one I tried which was the red one. I looked like a thin coat of cheap polish. :( I love Sally Hansen polish, but this one was not good.