Homebrew PCBs

For those who don't know, Vitrea 160 is a heat cured glass paint (as in 
for painting glass) which can be used as a DIY soldermask and is 
available easily at many art supply stores for a few dollars in a large 
number of colours.  The typical use is to use toner transfer to put 
toner on your pads, then brush (or better, spray with an air brush) a 
slightly diluted vitrea coating, allow to dry, then bake at 170-180 
Degrees C for 30 to 40 minutes (technically you're supposed to dry it 
for 24 hours, but I thin with methylated spirits, air brush it, and just 
allow it to dry for a couple hours before baking, no problems).  Once 
baked, acetone and a cotton bud will remove the toner leaving the pads 
clean.

Example produced today: 
http://www.flickr.com/photos/93638530@N08/11885554945/

It's not just for looks, it does do a reasonable job as a soldermask, 
once baked resistant to abrasion, chemicals etc and as long as there is 
flux around solder doesn't stick to it.

Anyway, long story short, it works well if you use toner transfer to 
mask out the pads, given it's only the pads you're transferring, that's 
not a great hardship but I'd rather use dry-film for masking the pads 
somehow.  I tried painting the board then applying & exposing & 
developing the resist over the top, and subsequently using a solvent to 
strip the paint from the now exposed pads, but the solvents I've tried 
are also happy to strip the resist off too.

Brilliant ideas anybody?