Sandy,
thanks for that input, great info. I've done a lot of Googling on this matter and this has led me to quite a few screenprinting forums. It always seems to be the same story: as far as non-dedicated inks go, the guys get the most opaque prints using genuine Epson black. However I don't recall any of them differentiating between M & P. After that the main inks used are the dedicated screen printing inks like Black Max and others, which are supposed to be very fast drying and absolutely loaded with UV blocking pigment.
G McCurdy,
when I first started on this PCB venture a couple of months ago, I bought a mono laser printer and it was useless. Lots and lots of Googling and I realised only a few were getting good enough results with a laser. It seems very brand/model dependant.
I came to learn that all the screenprinters were using inkjet with either genuine epson black ink (or dedicated screenprinting ink) + rip software which made the printer lay down much more ink. The other important factor was the inkjet transparency used. Any inkjet transparency just won't cut it. The guys seem to get greatly improved results using the transparencies dedicated to making film positives. They all seem to say one thing though, inkjet is the only way to get very opaque prints (providing the recipe is right).
I tried my Epson TX810FW and the first attempt was terrible. Back to mind numbing Googling and learning about print driver settings and I eventually ended up was a much darker/denser and uniform laydown of ink, but I still had to use 2 stacked films. That led me to the path I'm on now. The hardest part I'm finding is getting hold of the 2nd hand printers QTR supports.
Keith.