Some people are having good luck with
VHT in black.
I have not used it. See post #22 of the thread below for the pic of the product. But you must bake it to get proper curing and molecular bonding, or it will scratch off with your fingernail. It doesn't appear to be as good as PC, but it will get you an intro into what is possible. Other brands don't appear to work, and other colors of VHT don't appear to work well.
Here is a thread on it......
http://castboolits.gunloads.com/show...-lets-find-out