Screen printing PCB manufacturing:
Here is an example of Screen Printing PCB Manufacturing. It is very time consuming but your PCB factory could make screen printed t-shirts on the weekends. :) It looks like they are setup for medium volume but it looks very time consuming compared to modern PCB manufacturing.
Via Hacked Gadgets!

I work in a screen printing shop and have used epoxy inks (specifically enthone 50-series aka Hysol) as etch resist with great success. Although, I typically use mesh counts in the 250-280tpi range. The higher mesh count should greatly increase resolution. I have had no issue making boards for SMD components and 10/10 mil traces/spaces.
I make my prototype boards at work like this too. I mill registration marks on the sheet of circuit board so I can cnc drill and mill the board before or after acid etching. Heh, I thought this was too low tech for this site, so never shared.
LOL, house bricks……
Nice! I wonder where you get those inks? Also anyone know what it would cost to set up a rig like that?
The inks seem to be available on eBay .. try to search for “PCB paint”.