Digital BW, The Print

Olivier wrote:

> 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.

1/ another grey ink added does wonders, no I don't think that 
precision became much better, speed was more important, there 
must a trade off between the two  2/ Yes, I think the 9800 
range could be better for gloss printing in the first place 
and isn't as good for matte as the 9600 range was. At least we 
start to think that over here. The 9800 is also harder to 
adapt to third party inks. However with a  RIP it must be 
possible.

Pardon, I'm Dutch so it will not be proper English either. 
Combien d'encre par une goutellete (had to look up that word 
:-) 3.5 picoliter could be 3 or 4 picoliter.

> 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 (?).

To all the pro printers in time compared to the 
consumer/desktop models of the same generation.

>> 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 think you see it as a theoretical concept. I guess the Epson 
heads have their limitations as well. So is the hardware and 
software that drives them. The Canon pages I gave the link too 
may be exaggerating the limitations but they are revealing 
some basic requirements for further developments. For all the 
three inkjet head technologies. It is also interesting that 
Canon goes for a 16 bit driver with this technology. This 
could go two ways, at last there is the hardware that can 
represent the 16 bit smoothness, color accuracy and/or they 
need the 16 bit to get it all controlled.

> 
> 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 ?

For one reason or another it has always been hard to develop a 
continuous tone printing technology that has a high Dmax + 
consistency in output + sharp detail. That was so with 
Collotype, Screenless Offset, Conventional Rotogravure, 
Woodbury Type to add an odd one as the last. For process 
control you see that they don't push the pure concept but add 
better controllable technology and make it a hybrid process 
like the semi halftone in modern rotogravure shows. I think 
that inkjet right now is very close to the ideal that the 
other processes tried to achieve. With a hybrid of all tone 
forming elements known in printing as one only couldn't 
achieve that goal. Your infinite small droplets has it 
limitations as described. Best example that they tried before 
is the Iris printer with its continues one size droplet stream 
(though then with larger droplets). It had wonderful smooth 
gradations, good color but lacked sharp detail and the printer 
needed a lot of maintenance for consistent work. It has been 
replaced by the Epson head technology. The successor of the 
last could be Canon's new heads. It can pump a lot of small 
droplets to the right place, so they are trying again.

Ernst
                    --
           Ernst Dinkla


www.pigment-print.com
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