Homebrew PCBs

GC Electronics is under GC/Waldom   website does not tell you much 
as I believe that you have to be registered dealer to get to most 
information on the site.  They do give you access to there Dist. 
locator but think they are only U.S. and Canada that I saw.

Mouser  www.mouser.com I believe carries the GC Electronics resist 
pens but don't list them as GC Electronics.  They list two pen widths
1/32" and 1/64"   or .79 mm and .39 mm.  these list for $2.48 and 
$2.64 each    Page 1040 in Cat.#615

MG Chemicals has a resist pen  www.mgchemicals.com  I buy MG 
Chemicals thru Circuit Specialists  www.web-tronics.com  MG 
Chemicals pen is only listed for use with Ferric Chloride and Sodium 
Persulfate,  not for use with Ammonium Persulfate.

These pens look just like a Shapie, in fact I use a fine point 
Shapie to do touch up when needed on my boards, I use Ferric 
Chloride Etchant.

Ben