Homebrew PCBs

Hi Group,

I just tried a number of different searches to find and old thread (I 
believe it was in this group) discussing Ink to use for etch resist.  
The original poster was looking for Sharpie Ink and couldn't get it in 
small qty.  Someone suggested another type of ink that works and that 
you can get in small bottles.  Does anyone remember what this ink is 
and where to get it?

Thanks

Chris