My first attempt after reading this thread. Thanks for the inspiration!
This is the bottom of my YF-19b "Backlash" from my blog. It is unfinished, de-skinned PBIII. Need to figure out what to do in the center bottom...maybe a wrap around stripe. The top side is the better side, but I wanted to "practice" on the bottom. I did have a little trouble with paint sticking to the masks.
Sorry about the poor quality picture, I used my camera phone to hide the flaws!