Digital BW, The Print

I was just printing out some BO prints and was thinking about how  
Clayton had mentioned getting banding.  Which got me thinking about  
Paul's theory that if the printers are running on only one channel,  
it's just asking for problems.  So, it occurred to me, why not load  
all the channels with Eboni or split them up for 2K work, then  
linearize the output with QTR or IJC/OPM by mirroring the curves for  
the duplicated channels.  It seems to me that this might be an  
interesting way to get around the inherent weaknesses of printing  
with only one head.

Right now, I'm not really in a position to try it out, but thought I  
would mention it in case anyone might want to try it.

Eric,
www.ericashworth.net

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Eric Ashworth
<brigsby707@c...> wrote:
> I was just printing out some BO prints and was thinking about how  
> Clayton had mentioned getting banding.  Which got me thinking about  
> Paul's theory that if the printers are running on only one channel,  
> it's just asking for problems.  So, it occurred to me, why not load  
> all the channels with Eboni or split them up for 2K work, then  
> linearize the output with QTR or IJC/OPM by mirroring the curves for  
> the duplicated channels.  It seems to me that this might be an  
> interesting way to get around the inherent weaknesses of printing  
> with only one head.
> 
> Right now, I'm not really in a position to try it out, but thought I  
> would mention it in case anyone might want to try it.

Why not load half the carts with black, and half with diluted black
(you may have to tint the diluted black to get neutrality). Set it up
with QTR, and you'll have a machine that has better tonality than just
BO, runs for ages without a reload, and when you do need to reload,
all the blacks will be running out at about the same time, so reload
them all.

That was what I was alluding to regarding splitting up the channels  
for 2K work, that is black and light black say split 3 channels K to  
3 channels LK in a 6 ink printer or , 3 K, 4 LK in a 7 color. Also,  
depending on ink usage, you could use more channels for the LK if it  
were used up faster than the K ink.

The more I think about this, the more I'm thinking I might be picking  
up an R200 to experiment with.

I think I'd probably use Eboni for the K & then use the dark or mid- 
grey from the UT-FSN inkset. Unless someone had a better suggestion.

Eric
www.ericashworth.net


> > Why not load half the carts with black, and half with diluted black
> > (you may have to tint the diluted black to get neutrality). Set  
> it up
> > with QTR, and you'll have a machine that has better tonality than  
> just
> > BO, runs for ages without a reload, and when you do need to reload,
> > all the blacks will be running out at about the same time, so reload
> > them all.


[Non-text portions of this message have been removed]

Hi Eric;

This will work, I don't see why it shouldn't but with all those 
channels firing you'd likely lose one of the defining 
characteristics of BO- namely the mid-tone & highlight luminosity 
that results from allowing some paper white to show through the 
dots. 

One interesting thing about QTR is that the 'calibration' mode 
target allows you to see which channels are banding, and which are 
smooth. I would suggest that as a starting point, you could put your 
Eboni and LK in the two smoothest channels, and put diltuted warm 
and cool toners in 2 or three of the others. I suppose you could put 
a PK in one channel also, and have glossy printing available as 
well. In other words, something similar to Paul's inksets, but BO or 
2K, and run with QTR on your choice of channels.

If you set up your curves on one of the glossy paper settings, you 
will have 'photo RPM' available (that;s the 5770 dither) which 
produces very fine, smooth BO and even smoother 2K, assuming no 
dither banding





 In DigitalBlackandWhiteThePrint@yahoogroups.com, Eric Ashworth 
<brigsby707@c...> wrote:
> That was what I was alluding to regarding splitting up the 
channels  
> for 2K work, that is black and light black say split 3 channels K 
to  
> 3 channels LK in a 6 ink printer or , 3 K, 4 LK in a 7 color. 
Also,  
> depending on ink usage, you could use more channels for the LK if 
it  
> were used up faster than the K ink.
> 
> The more I think about this, the more I'm thinking I might be 
picking  
> up an R200 to experiment with.
> 
> I think I'd probably use Eboni for the K & then use the dark or 
mid- 
> grey from the UT-FSN inkset. Unless someone had a better 
suggestion.
> 
> Eric
> www.ericashworth.net
> 
> 
> > > Why not load half the carts with black, and half with diluted 
black
> > > (you may have to tint the diluted black to get neutrality). 
Set  
> > it up
> > > with QTR, and you'll have a machine that has better tonality 
than  
> > just
> > > BO, runs for ages without a reload, and when you do need to 
reload,
> > > all the blacks will be running out at about the same time, so 
reload

> > > them all.
> 
> 
> [Non-text portions of this message have been removed]

I’m not so sure.  If the paper white does not show through, the density will
be darker, and the linearization will shift it back open.  If the scheme
allows smaller dots with more uniform distribution, there could be something
there, but just firing more black nozzles does not seem like a direct way to
that goal.  It’s interesting, so please keep us posted.

I posted a question in the QTR forum asking when we might see the additional
and updated dither algorithms of gimp-print 5.0 show up in QTR.  How they
might show improvement with QTR is unclear to me, all the release notes on
them refer to color channel operations.

Best regards,
John Moody

-----Original Message-----
From: DigitalBlackandWhiteThePrint@yahoogroups.com
[mailto:DigitalBlackandWhiteThePrint@yahoogroups.com]On Behalf Of Steven
Karafyllakis
Sent: Friday, August 26, 2005 9:02 AM
To: DigitalBlackandWhiteThePrint@yahoogroups.com
Subject: [Digital BW] Re: Dedicated BO or 2K printer was (Attn: Clayton or
interested BO printers)

Hi Eric;

This will work, I don't see why it shouldn't but with all those
channels firing you'd likely lose one of the defining
characteristics of BO- namely the mid-tone & highlight luminosity
that results from allowing some paper white to show through the
dots.

One interesting thing about QTR is that the 'calibration' mode
target allows you to see which channels are banding, and which are
smooth. I would suggest that as a starting point, you could put your
Eboni and LK in the two smoothest channels, and put diltuted warm
and cool toners in 2 or three of the others. I suppose you could put
a PK in one channel also, and have glossy printing available as
well. In other words, something similar to Paul's inksets, but BO or
2K, and run with QTR on your choice of channels.

If you set up your curves on one of the glossy paper settings, you
will have 'photo RPM' available (that;s the 5770 dither) which
produces very fine, smooth BO and even smoother 2K, assuming no
dither banding





[Non-text portions of this message have been removed]

John;

This might be true for the very upper end, but the mid-tones might get 
completely inked over. Wether or not that's undesirable is of course a 
matter of personal taste.

Steve Karafyllakis

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "John Moody" 
<moodymz3@y...> wrote:
> I'm not so sure.  If the paper white does not show through, the 
density will
> be darker, and the linearization will shift it back open.

My initial idea for doing this was based on using a set of piezotone  
carts for the 1280 with QTR. Since the two lightest grays are  
duplicated, ie: two channels each, it took some conniving to get  
things to print acceptably with all six channels.  Before I knew  
about the copy curve function, I simply set up two four channel  
curves, using one pair of mid-grey/light-grey channels for one curve  
and the other pair for the other.  Then, to print I blended the two  
curves 50/50.  The result was generally smoother than the individual  
curves. By printing the ink separation page in the QTR setup through  
the finished and blended curves, I was able to verify that the output  
of the two mid-grey and two light-grey channels were approximately  
halved in order to produce the proper ink density for the same range  
of each of the individual curves. Hence, the light bulb in me brain!

I'm not so sure that having multiple channels with Eboni would kill  
the white of the paper. The general way I was going to approach the  
problem was to produce a curve and linearization for a single  
channel, then copy the curve to the duplicated channels.  Then, to  
control the density of the multi-channel output, I would use a little  
trial and error with the ink limits. Therefore, at no point in the  
combined curves would any one channel be producing full output.  Just  
as a guess, it seems that if you had four channels, the ink limit for  
each for maximum dmax would be around 25%.  In essence, the benefit I  
envisioned would be that any failings in the output of one channel  
would be offset by one of the others.  And, since the density would  
be produced by adding multiple "layers?" or more accurately, more  
concentration of ink, there would still be virgin paper visible in  
order to produce the gradient.

I think the bottom line is that I've got to get me a printer to play  
with, and a densitometer to linearize the curves properly rather than  
fiddling with my scanner. Then when I've got some results rather than  
theory I can see if this is plausible or just a side effect of an  
overactive imagination ;-P

Will definitely keep you posted on my results.

Eric
www.ericashworth.net