craftgrrl | micron pens and barbie skin

I've heard several of you dollmakers praising micron .005 pens for doing fine detailing, especially around the eye area. However, I've never been able to get them to work - they always either don't lay any pigment down and then instantly die when touched to a repainted barbie eye, or they yield a small bit of pigment and then poop out, never to be revived. I've tried several different brands, tested them out in the store to make sure they worked, etc, and have always gotten the above results.

So I've been making do with small brushes for black outlining and such, but my current project is a mermaid with a full-body traditional Japanese tattoo, and a black pen for outlining would be a huge help. (For example, this is what's on her back.)

Has anyone else had this problem with pens, and what did you do about it? I use Liquitex paint, in case it matters.