Digital BW, The Print

Jeff,

You wrote:

>Can someone explain why the "visual densities" of the original
>quadtone ink set (as printed on paper) are bunched at the dark end of
>the grayscale (4-45, 4-50, 4-75 are all very dark)?  Seems to me that
>if the visual densities were more evenly spread out over the grayscale
>spectrum that we could produce more evenly and smoothly transitioned
>RGB partitions that use all the inks.  ...

To judge ink densities, I print the 21-step test file using what I call my
"Color Test" curve.  (The driver settings I use for this include Matte HW
paper type and No Color Adjustment.) This basically pumps out 100% of each
ink at a different part of the test strip.  Then I scan the test strip and
do a levels on it.  So, black is 100% and white is 0% when measured with the
eyedropper in Photoshop (if the image is in grayscale mode).

Scanner settings, etc. can affect results, so I use the tool just to compare
inks -- and mix new brews.

Piezo gives results as follows: K = 100, C = 84, M = 38, Y = 27%.

When I worked up the MIS VM inkset, I didn't just clone Piezo, even though I
was already using the Piezo variable-tone formula that just accepted the
Piezo densities.  Rather, I tried a number of density combinations and found
that, under the loupe, as the middle ink got closer to the black ink, the
dots at about 30% on the 21-step test file print increased.  As the middle
gray got closer to the light gray, the dots at about 70% increased.  The
optimum density that minimized the dots was so close to Piezo, that I ended
up right where Piezo is.  That is, for a 3 ink mix, the 100, 84, 38% spread
was about optimum.  Since I was interested in making a standard that would
have competitive sources of ink readily available, it also made sense to
have the MIS VM inkset as close as possible to the Piezo and variable-Piezo
that I was using.  (Since the 38% give dotless highlights on the 1160, the
lighter ink was simply irrelevant -- that position became the toner position
on quad printers.)

The MIS standard quads are as follows on my Color Test:
K = 100, "75" = 96, "50" = 79, "25" = 24%.

I don't know the reasons or history of why MIS chose this density
distribution.  In my view the gap between 24% and 79% is too much for my
purposes.  On the other hand, I expect it produces a more linear g/s density
distribution than the Piezo/MIS VM & FS distribution when it is simply
printed through the Epson driver with no curves or other quad workflow.  It
no doubt also produces dotless highlights in even a 3000 when a partitioning
workflow is used.

Paul
http://www.PaulRoark.com

Paul,
 
I suppose that MIS Full Spectrum quads densities are very similar - if not
equal - to Piezo, given that these inks are also known as "Cone clone". Am I
right? I have a set on its way to my eager hands, and I was planning to
measure densities as well, but if you already did it I'd definitely trust
your results rather than mine.
 
Alessandro Pardi

-----Original Message-----
From: Paul Roark [mailto:paul.roark@...]
Sent: giovedì 1 novembre 2001 22.07
To: DigitalB&WPrint
Subject: [Digital BW] Quad Ink Densities



To judge ink densities, I print the 21-step test file using what I call my
"Color Test" curve.  (The driver settings I use for this include Matte HW
paper type and No Color Adjustment.) This basically pumps out 100% of each
ink at a different part of the test strip.  Then I scan the test strip and
do a levels on it.  So, black is 100% and white is 0% when measured with the
eyedropper in Photoshop (if the image is in grayscale mode).

Scanner settings, etc. can affect results, so I use the tool just to compare
inks -- and mix new brews.

Piezo gives results as follows: K = 100, C = 84, M = 38, Y = 27%.

 <huge snip> 



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

Me too! I'll post my impressions when they arrive. Another HUGE advantage
over IJM for outside US customers is that they give you a choice of shipping
methods, one of which is good 'ol airmail - so a good chance of no taxes.

Julian

Julian

----- Original Message -----
From: "Alessandro Pardi" <alessandro.pardi@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Monday, November 05, 2001 5:58 PM
Subject: RE: [Digital BW] Quad Ink Densities


Paul,

I suppose that MIS Full Spectrum quads densities are very similar - if not
equal - to Piezo, given that these inks are also known as "Cone clone". Am I
right? I have a set on its way to my eager hands, and I was planning to
measure densities as well, but if you already did it I'd definitely trust
your results rather than mine.

Alessandro Pardi

-----Original Message-----
From: Paul Roark [mailto:paul.roark@...]
Sent: gioved\ufffd 1 novembre 2001 22.07
To: DigitalB&WPrint
Subject: [Digital BW] Quad Ink Densities



To judge ink densities, I print the 21-step test file using what I call my
"Color Test" curve.  (The driver settings I use for this include Matte HW
paper type and No Color Adjustment.) This basically pumps out 100% of each
ink at a different part of the test strip.  Then I scan the test strip and
do a levels on it.  So, black is 100% and white is 0% when measured with the
eyedropper in Photoshop (if the image is in grayscale mode).

Scanner settings, etc. can affect results, so I use the tool just to compare
inks -- and mix new brews.

Piezo gives results as follows: K = 100, C = 84, M = 38, Y = 27%.

 <huge snip>



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


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Alessandro,

You wrote:

>I suppose that MIS Full Spectrum quads densities are very similar - if not
>equal - to Piezo, given that these inks are also known as "Cone clone".
>Am I right?

They are very close, and they should be the same.  I'd assume they are a
feasible substitute with at most minor corrections.

To be honest, I haven't actually tried the production FS inks to see why
some users thing there needs to be a slight correction in the Piezo driver
dot gain (or whatever it is) box.  I'm wondering if MIS missed the densities
slightly.  Given all the density fluctuations with the Piezo and CIS
combination, it may be that some of that affected the design criteria, but
I'm guessing.  (I was not involved in finalizing the mixing ratios.) On the
other hand, what I've found with the MIS VM system is that some Piezo
customers got used to their malfunctioning Piezo/CIS systems and thought the
distorted g/s ramp was normal. So, they may be "correcting" the system to
replicate their mal-functioning Piezo/CIS systems.

Basically, though, the big picture is that the MIS VM, FS and Piezo inks are
about the same.  I'm trying to establish an open system with competing inks
and workflows so that no one company can get a monopoly and stick it to us.
B&W photo has always been a technology that is affordable and easy for
creative types to use and manipulate.  I want to be sure it stays that way.
So, if the FS densities aren't right on, I'll get some and see what can be
done to correct the situation.

I might add that I've detected density differences between batches of inks
from the same company (both Piezo and MIS). There is no such thing as total
accuracy here.

However, one reason we need the ink companies to do our basic ink mixing is
that my quick and dirty syringe mixing is not accurate enough to give
sufficient consistency.  One needs very accurate scales and large volumes to
be even close to consistent with some of these critical ratios -- I'm
talking three digits of accuracy.  The light inks are affected by changes in
their mixing ratios to the hundredths of a percent.

> I have a set on its way to my eager hands, and I was planning to
>measure densities as well, but if you already did it I'd definitely trust
>your results rather than mine.

Well, you really need to compare, for example, Piezo and the FS inks on the
same system with the exact same materials.  The density ratios I put out
there are what I get for my system.  All systems are a little different.
So, get the curve, 21-step test file, and print some Piezo (from a cart --
not an old CIS that may have affected densities) and see what densities you
come up with.  Then try the other ink and compare.  Expect + or - 1-2% just
from printer variances.  Even high end 7000s and drum scanners don't seem to
be more consistent.  Perfection is impossible here.

Paul
http://www.PaulRoark.com

___________________________________

Alessandro Pardi

-----Original Message-----
From: Paul Roark [mailto:paul.roark@...]
Sent: gioved\ufffd 1 novembre 2001 22.07
To: DigitalB&WPrint
Subject: [Digital BW] Quad Ink Densities



To judge ink densities, I print the 21-step test file using what I call my
"Color Test" curve.  (The driver settings I use for this include Matte HW
paper type and No Color Adjustment.) This basically pumps out 100% of each
ink at a different part of the test strip.  Then I scan the test strip and
do a levels on it.  So, black is 100% and white is 0% when measured with the
eyedropper in Photoshop (if the image is in grayscale mode).

Scanner settings, etc. can affect results, so I use the tool just to compare
inks -- and mix new brews.

Piezo gives results as follows: K = 100, C = 84, M = 38, Y = 27%.

<huge snip>

Paul, just thinking out loud here... I've never got my hand on a 7000, so I
don't know how the ink carts work, but should it possible to bulk load FS
and print through the cone rip?

Julian
----- Original Message -----
From: "Paul Roark" <paul.roark@...>
To: "DigitalB&WPrint" <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Monday, November 05, 2001 7:01 PM
Subject: RE: [Digital BW] Quad Ink Densities


> Alessandro,
>
> You wrote:
>
> >I suppose that MIS Full Spectrum quads densities are very similar - if
not
> >equal - to Piezo, given that these inks are also known as "Cone clone".
> >Am I right?
>
> They are very close, and they should be the same.  I'd assume they are a
> feasible substitute with at most minor corrections.
>
> To be honest, I haven't actually tried the production FS inks to see why
> some users thing there needs to be a slight correction in the Piezo driver
> dot gain (or whatever it is) box.  I'm wondering if MIS missed the
densities
> slightly.  Given all the density fluctuations with the Piezo and CIS
> combination, it may be that some of that affected the design criteria, but
> I'm guessing.  (I was not involved in finalizing the mixing ratios.) On
the
> other hand, what I've found with the MIS VM system is that some Piezo
> customers got used to their malfunctioning Piezo/CIS systems and thought
the
> distorted g/s ramp was normal. So, they may be "correcting" the system to
> replicate their mal-functioning Piezo/CIS systems.
>
> Basically, though, the big picture is that the MIS VM, FS and Piezo inks
are
> about the same.  I'm trying to establish an open system with competing
inks
> and workflows so that no one company can get a monopoly and stick it to
us.
> B&W photo has always been a technology that is affordable and easy for
> creative types to use and manipulate.  I want to be sure it stays that
way.
> So, if the FS densities aren't right on, I'll get some and see what can be
> done to correct the situation.
>
> I might add that I've detected density differences between batches of inks
> from the same company (both Piezo and MIS). There is no such thing as
total
> accuracy here.
>
> However, one reason we need the ink companies to do our basic ink mixing
is
> that my quick and dirty syringe mixing is not accurate enough to give
> sufficient consistency.  One needs very accurate scales and large volumes
to
> be even close to consistent with some of these critical ratios -- I'm
> talking three digits of accuracy.  The light inks are affected by changes
in
> their mixing ratios to the hundredths of a percent.
>
> > I have a set on its way to my eager hands, and I was planning to
> >measure densities as well, but if you already did it I'd definitely trust
> >your results rather than mine.
>
> Well, you really need to compare, for example, Piezo and the FS inks on
the
> same system with the exact same materials.  The density ratios I put out
> there are what I get for my system.  All systems are a little different.
> So, get the curve, 21-step test file, and print some Piezo (from a cart --
> not an old CIS that may have affected densities) and see what densities
you
> come up with.  Then try the other ink and compare.  Expect + or - 1-2%
just
> from printer variances.  Even high end 7000s and drum scanners don't seem
to
> be more consistent.  Perfection is impossible here.
>
> Paul
> http://www.PaulRoark.com
>
> ___________________________________
>
> Alessandro Pardi
>
> -----Original Message-----
> From: Paul Roark [mailto:paul.roark@...]
> Sent: gioved\ufffd 1 novembre 2001 22.07
> To: DigitalB&WPrint
> Subject: [Digital BW] Quad Ink Densities
>
>
>
> To judge ink densities, I print the 21-step test file using what I call my
> "Color Test" curve.  (The driver settings I use for this include Matte HW
> paper type and No Color Adjustment.) This basically pumps out 100% of each
> ink at a different part of the test strip.  Then I scan the test strip and
> do a levels on it.  So, black is 100% and white is 0% when measured with
the
> eyedropper in Photoshop (if the image is in grayscale mode).
>
> Scanner settings, etc. can affect results, so I use the tool just to
compare
> inks -- and mix new brews.
>
> Piezo gives results as follows: K = 100, C = 84, M = 38, Y = 27%.
>
> <huge snip>
>
>
>
>
> Please visit the Group Homepage to check the Files, Bookmarks, Polls and
other resources as they are often being updated. The page is at:
>
> http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint
>
> Please follow these basic guidelines:
> - Include your full name with your message.
> - Include the address of your website, if you have one.
> - As threads develop, trim off excess portions of earlier messages to keep
them short.
> - As the topic of a thread changes remember to change the subject header.
> - Good manners are required at all time. No personal attacks or "flames."
> - Complete your Yahoo profile.
> - Before posting a question, search the message archives and the various
resources on the homepage.

>
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>

Paul,
 
I must have missed something: where do I get the "color test" curve and
where exactly do I have to look on the scan from the 21-step scan for the 4
inks densities?
 
Thanks, 
Alessandro Pardi

-----Original Message-----
From: Paul Roark [mailto:paul.roark@...]
Sent: lunedì 5 novembre 2001 19.01
To: DigitalB&WPrint
Subject: RE: [Digital BW] Quad Ink Densities



All systems are a little different.
So, get the curve, 21-step test file, and print some Piezo (from a cart --
not an old CIS that may have affected densities) and see what densities you
come up with.  Then try the other ink and compare.  Expect + or - 1-2% just
from printer variances.  Even high end 7000s and drum scanners don't seem to
be more consistent.  Perfection is impossible here.

Paul
http://www.PaulRoark.com <http://www.PaulRoark.com> 





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