Digital BW, The Print

> I have made a step wedge for QTR with some checks on bleeding.
> Usually on good papers the Dmax stops increasing before the
> bleeding gets ugly. Looks like the chemists have an idea how
> to keep the print characteristics of the ink under control.

Yes, I experienced +/- the same : except EEM (and I don't know why), 
all VFA, USFA, HPR and so-called fine art papers "hold" ink pretty 
well. In fact, I'd have expected a little bleeding in total black 
areas (99-100) would have provided total coverage while retaining 
Dmax, hence my question. 
 
> You can bet that Epson engineers fix the relation between the
> different dotsizes on an average dotgain. So not a 1:2:4
> relation on dot area but a 1:2:4 relation on actual density
> measured in tests on several papers. 

Which turns for us, users, uncontrollable. But that a fair technical 
proposal from Epson, since I'd assume the driver then turns to be a 
nice piece of complexity.


You run into a different
> problem with smaller dots, the placing of the smaller dots
> gets far more irregular than they are with larger dots. The
> differences between smaller droplet contents is higher than
> between larger droplets contents. 

Ok, you have a point. With the new x800 generation, do you feel 
(finger in the air) that 1)this physical precision has improved, 2) 
the new K3 resin-coated formulation plays a big and different role in 
dot gain, overprint effects...What makes me think this is that the 
OEM calibration Colorbase can only be used in 2880dpi whichever media 
type.

I'm sorry I can't get the translation of a "droplet content". I'm 
French.

The pro printers almost
> always had larger droplets than the desktop models and Epson
> mentioned that consistency of droplet size was more important.
> So you either choose for a more precise dot placement but
> slightly rougher screen or you go for a finer dot with more
> fluctuation in the density and in detail. The Dmax will not be
> better at 100% when there's no white left. The control of the
> 95-100% range isn't better with smaller dots either.

That partly replies the above, but you might refer to the x600 
printers (?).

> There's a good piece of PR on the new Canon FINE heads here:
> 
> http://consumer.usa.canon.com/pixma/press/FINE_TG_0909.pdf


I've read through it, but will properly study it cool headed.

 
> At the highest resolution the number of droplet sizes get
> less. The evolution we have seen  with increased resolution is
> a smaller minimum droplet size, more droplet sizes, more grey
> inks. For a good reason as just making droplets smaller isn't
> working.

I'd have thought that all those elements precisely call for smaller 
drops. Basically, if the purpose is smoothness, maximum shades 
reproduction (grey values), detailed prints and media coverage,... 
one has to combined a precisely built head (your link) to be capable 
of as small as possible dots (for smoothness and dotless prints) 
dithered by a first-class driver (for the best trade off between 
value/detail) with a variable density ink set (for maximum shades 
reproduction) with ink formulation that combines both right pigment 
load and eventually low dot gain.

I've seen K3 lacking a L-LLK, and somehow lacking (a bit) Dmax, so 
I'm at a stage where I wonder whether on principle highest dpi 
setting for smallest drop possible would eventually better the print 
at all levels without generating issues like dot registration, drop 
size... I also count on a reasonnably long overlap and some 
significant extra K blackboost to smooth the print yet give good 
Dmax. 

Does that all make sense or not worth trying ?

Olivier