Stefan Trethan wrote:
> i am not too convinced that the "darkness" is most important to be
> measured...
>
> do you really have problems with the whole printout being not dark enough?
Not really.
I've mainly used epson stuff which is very dark, so I've never
had problems with overexposure. I've also made a couple of boards
using the HP stuff, which isn't as dark (sorry I can't give you
relative absorption numbers :)) and also didn't have problems
with overexposure.
I agree that line edge jaggedness and pin holes are more
important than overall darkness since many of the inkjets I've
tested seem to look dark enough so that exposure times can be
resonably flexable (+-30%). However the most importantly defect
is banding due to blocked or partly blocked jets. This can easily
create a discontinuity in a track. Other problems are ink
splattering which I have seen with some refillable inks on my
Epson. If the splattering is severe enough it can actually create
a short between closly spaces tracks.