Homebrew PCBs

Hi guys,

i have tryed to use a water resistent photo emulsion made for
serigraphy, as etch resist in ferric cloride etchant, and it seems it
was a very bad investment.
 I have seen in the archive that there are some emulsions that do work
as etch resist, and also adhere to the metal.
 Can someone please tell me which emulsion works ?

i have user ulano 995wr (diazo sensitizer and Polyvinil-Acetate base)
and this one doen not work....it bubbles off in the etchant.(i guess e
very small amount of etchant is penetrating through, and makes the
emulsion loose contact to the metal)

thanks for any information on this,
Mihai