Homebrew PCBs

I failed to hit the answer to this with a search but I'm sure it has 
been described.

I have a Sears Craftsman dremel tool I bought some time ago and kept in 
storage and never used.  It came with a bunch of tools.  It seems as 
though I've heard of people fashioning simple pc boards by removing 
copper from a board leaving pads and traces and such.  Can someone 
describe the tool they use to do this?  And can you describe about how 
fine a feature you're able to make this way?

Thanks,

Coop, aa1ww