Thanks everyone. R2- you're right, I do need a better background. I finally got a new digital camera right before Christmas, pretty much exclusively for taking pix of pens! But I haven't yet ventured into finding a really great looking background.
This cast was actually just the shimmery white color, but I got some of that fasflip color changing stuff and decided to try it on the inside of the blank. It didn't come out to change colors like that stuff, b/c it wasn't transparent enough, but it gave that black shine underneath, so I was still happy with it and thought it was a neat look. Now I have to cast something in clear, so I can use the fasflip like it's supposed to be used.