Homebrew PCBs

Grant,

The UV etch resist ink I use was made by LeaRonal in Freeport, NY but 
they are no longer around. They were bought out by another firm but I 
can't remember who that was. There are several suppliers who offer 
these inks, check out Enthone and MacDermid. If a supplier offers 
soldermask, they will usually have the etch resist. I had a gallon of 
this ink left over from my commercial shop and even though its date 
code had expired it still works good. We thin the ink a bit with a 
special solvent for UV inks. 

If you are just getting started with screen printing I would suggest 
getting the air dry etch resist. This type of resist is inexpensive 
and works good. Buy the smallest quantity they offer. These inks will 
cover about 3000 square feet per gallon when using a 305 mesh 
polyester screen.

If you want to try out the soldermasking process get a single or two 
part epoxy soldermask. You can use an old electric kitchen oven to 
cure the soldermask. It takes about 30 to 60 minute to cure depending 
on the temperature. This really makes your boards look good.

BTW, the screen printing emulsions are negative acting so you will 
need positive films emulsion side up. 

Tom