Hello,
Thanks for answers regarding finding the appropriate density. The
density wedge is the way to go it seems. Another question comes to my
mind: would you put process colour step wedges on the same sheet to
determine the dotgain, or in a next printing run with the same density
across the width of the sheet?
I'm asking this, because when you take the route of the density wedge
to find the appropriate density, you must put the step wedges in one
row, perpendicular to the density wedge. Say you find that zone 14 has
the best density for cyan, you then look in that particular zone for
the cyan step wedge to determine the corresponding dotgain.
But: density can vary across the sheet in the printing direction. You
risk writing down dotgain results for an area that does not have the
same density as at the bottom of the page. I recently measured M 1.54
at the bottom of a page, M 1.44 in the middle op the page where the
step wedge was, and 1.54 again at the top. Dotgain for M at the bottom
was 19%, and 17% in the middle. No big deal maybe? I realise that after
putting appropriate correction curves in the rip to compensate for
extra dotgain, a new print run is needed to verify the results.
Sorry to bother you with all this, but practical advice is hard to find.
Have a nice weekend,
Yann Bouckaert
Sagam NV
Drongen, Belgium
Hello,
I would like to know what would be the fastest way to find the correct
wet densities on a printing press to match the solid primary colours as
stated in ISO 12647-2.
What I learned from the documentation that accompanies the Altona Test
Suite, you start with underinking, measure the solids in L*a*b* and
continue to rise the densities until the originally falling delta E's
start rising again.
I'm in the middle of implementing this standard on one sheedfed and two
web presses. To find correct densities, I started off with asking the
printer his normal working densities (eg. C 1.40, M 1.35, Y 1.20, K
1.70), took 0.2 off (C 1.20, M 1.15 etc) and let him continue to print
until about 0.3 higher than normal with intervals of + 0.05. The layout
of the sheet was the normal one I use to profile a press; it has solid
tone bars at the bottom. I asked them to try to print the sheet with
the same density with a minimum deviation of 0.05 across the sheet.
Because the printer did not have some sort of automatic density
control, it took them almost two hours to finish the series on one
paper type. At 40.000 sheets per hour a lot of paper was wasted.
The result was that I could indicate per ink what density gives solid
colours what are within ISO standard, but I'm not sure if the route I
took was the most efficient. I was thinking if it would be wiser to
print sheets with low densities on one side, and gradually rising the
ink level going to the right side of the sheet? At the left then you
would have eg. CMYK = density 1.0 and then smoothly going to the right
where the densities for CMYK are 2.0? Of course right after picking a
sheet you would have to measure the wet densities and write them down
for as many zones as you can.
I tried to find anything on this matter on the internet, but found
nothing. If there is something to find, or people are giving training
on this matter, please let me know. Willing to travel :-)
Any help is very welcome, and thanks for reading this long letter.
Cheers,
Yann Bouckaert
Sagam NV
Drongen, Belgium
Dear Sir/Madam
We are currently using a PhaseOne H20 digital
camera back. We have been shooting images for the web offset print market.
With this we use the supplied colorsync profile Phaseone H20 product Flash.
We have found this a good base to start from regarding colour retouching to
the original products. We are now going into the gravure print market. As
you will well know this is a different end result. Is there an icc profile
suitable for our camera that we can use for the gravure printing process.
Regards
Mick
--
M A Davies
Technical/Production Manager
WK360
01582 456082
07986 507980
Andy, Paul
Thanks for your comments, I do agree that everything being to the same standard is the ideal. However... As far as editing the advertising to suit the conditions, the problem is that we have neither the time nor resources to be changing files that the publisher doesn't want to pay for. The page rate for these jobs is such that making a profit on what you're being paid to do is hard enough, let alone doing things that nobody wants to pay for. As such, we do not touch the advertising content. They are proofed to an agreed standard, which the printers are obliged to match, and from there any problems the publisher wears. I think I should also make it clear that we are not a printer, however they are obliged to match our proofs, which are to the Australian DDDAP standard. Our editorial content is prepared to suit the printing conditions, and in this respect we do have a close relationship with the printers that the files are going to.
Bee
Belinda Beckinsale
Sinnott Bros Pty Ltd
Unit 4/85-91 O'Riordan St, Alexandria 2015
Ph: (02) 9353 9527, Fx: (02) 9313 4597
Hi
Thanks for your responses.
Paul - unfortunately converting everything to a set CMYK is not an option, we only have control over the editorial content, not the advertising. We don't touch it at all. Evrything that we actually process gets converted to a CMYK profile apprpriate to our conditions (Australian, mainly web fed).
Chris - You're right, I probably am overstating the problem. I know from experience that in the shadow areas a non 'perfect' gray balance will not really matter, especially with GCR. However, try to convince scanner operators who are set in their ways that it doesn't matter that the figures aren't what they expect, it's right for the process. They are starting to understand that figures don't matter so much anymore, but it's a (very) slow process. My main concern is when profiles are built with UCR rather than GCR (which is quite common in Australia, GCR is usually more common in newsprint), especially with all those horrible stainless steel appliances that are so fashionable at the moment. Here gray balance traditionally has dictated that the yellow should always be slightly above the magenta, whereas most profiles tend to have it lower (SWOP, ISO etc). This is where most of the head butting with scanning comes in...
However, you have confirmed my fear, that at press time there will have to be compromise when files come from different areas. Unfortunately at this stage we don't live in a perfect worldand for now we'll have to live with it.
Thanks, Bee
Belinda Beckinsale
Sinnott Bros Pty Ltd
Unit 4/85-91 O'Riordan St, Alexandria 2015
Ph: (02) 9353 9527, Fx: (02) 9313 4597
Hi, all
What is the standard(ideal) setting for converting an image to be printed as CMY instead of CMYK?
I'm usig Photoshop's Edit-Color Settings-GRC-Black None; but I need to convert the CMYK image to RGB and then CMYK again, is this the right way of doing so?
Thanks for any imput.
Dennis Tan
Email: flexolist(a)yahoo.com
Mobile: +6012-305-3580
---------------------------------
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New and Improved Yahoo! Mail - 100MB free storage!
I have a question that has been bothering me about the the gray balance not being set to traditional standards.
I can understand the concept that the profile will make the yellow appropriate to what the press is actually printing, but what happens when you get a job on a press that has been imposed with files from a number of different suppliers. We work with a lot of magazines, and many of the advertising pages are supplied pdf files that are sent straight to the printer (ie we do not do the colour work on them). If an imposition contains some pages that have been set using traditional gray balance (eg 75 65 65 90 etc) and some pages that have been done using a profile such as the ISO web coated that uses a very different gray balance, with a lot less yellow, then how is the printer meant to handle balancing two very different gray balances in the same sheet? If the case is that print does have a lot more yellow in the shadow, and therefore less in the profile (which has been the case in all the press profiles that I have built), this obviously isn't a new thing since the advent of colour management, so why are our traditional gray balances suddenly seen as being wrong? This may not be a problem with ISO or SWOP profiles that have GCR and aren't really relying on CMY to make neutrals, but what about when the idea of tailor making your own profiles to suit your press really takes off, and different separations and black generations get used? Is there perhaps a case for a gray balanced CMYK 'working space' like there is in RGB? (ie work is done in this space and then converted to the appropriate press space). This would probably cause less arguments with scanner operators. Lets face it, the ideal RGB workflow is still not a workable reality for a lot of pre-press.
Also, there was a comment earlier that you don't want to set your scan range in RGB from 0 to 255 for the same reason that you would not set it to 0 to 100 for CMYK. I'm just wondering if this is unecessarily limiting the range of the scan. You don't actually print the RGB scan, it gets converted to a CMYK profile which would then handle what can actually be printed from that data (if that makes sense). Maybe I haven't fully thought through the logic of this, but any yays or nays would be appreciated.
Thanks for the rant
Bee
Belinda Beckinsale
Sinnott Bros Pty Ltd
85-91 O'Riordan St Alexandria NSW 2011
bbeckinsale(a)sinnottbros.com.au
Ph (02) 93539527
The overriding reason for RGB equal value producung neutral and CMYK needing different values for cyan and the magenta - yellow is the colour or
spectral response of the ink set.
Yellow is the best ink but cyan and magenta have large transmission errors. Magenta is contaminated with yellow and a little cyan - cyan ink is
contaminated with magenta and yellow.
To produce a neutral in CMYKthe grey balance must be altered to remove the imbalance caused by the contaminants. The balack also helps to build up
density lost by balancing the ink set to make neutrals.
eci-en-request(a)lists.transmedia.de wrote:
> Send ECI-EN mailing list submissions to
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>
> To subscribe or unsubscribe via the World Wide Web, visit
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> or, via email, send a message with subject or body 'help' to
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>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of ECI-EN digest..."
>
> Today's Topics:
>
> 1. Re: RGB to CMYK with ISO web coated profile (Andy Psarianos)
> 2. Re: RGB to CMYK with ISO web coated profile (Chris Murphy)
> 3. Re: RGB to CMYK with ISO web coated profile (Peter Kleinheider)
> 4. Re: RGB to CMYK with ISO web coated profile (Paul Sherfield)
> 5. Re: RGB to CMYK with ISO web coated profile (Peter Kleinheider)
>
> --__--__--
>
> Message: 1
> From: Andy Psarianos <andy(a)psarianos.com>
> Subject: Re: [ECI-EN] RGB to CMYK with ISO web coated profile
> Date: Tue, 3 Aug 2004 21:46:12 +0100
> To: eci-en(a)lists.transmedia.de
> Reply-To: eci-en(a)lists.transmedia.de
>
> Paul,
>
> Thanks that's really helpful.
>
> Yes indeed I am talking about the latest release of the profile called
> "ISO web coated"
>
> For example if I convert the following values I get the following
> results.
>
> From RGB Adobe 1998:
>
> RGB 50,50,50 to "SWOP" CMYK = 70,64,63,62
> (C highest and M and Y are similar values)
>
> RGB 50,50,50 to "ISO web coated" CMYK = 64,53,48,71
> (C highest M in middle and Y lowest)
>
> I'm not saying SWOP is correct, but if I were to remove the black
> separation it would appear grey wouldn't it? I don't believe the values
> in the ISO web coated values would be neutral. If this is the case, the
> question is why?
>
> I do understand that the lack of yellow in the dark greys could be
> hidden by the heavy black, but I don't understand why this was done,
> and why a more "conventional & balanced grey" was not chosen. Is it
> simply that when printing shadows with equal amounts of m and y they
> have a "yellowish hue" or is this an ink trapping issue?
>
> Overall, all tests I've done with the ISO web coated profile in
> conversions results have been very good. I'm willing to accept that
> these "unconventional values" in principle are OK, although I have
> several sceptics here which I need to convince.
>
> I would like to know what the reason was for this choice, if indeed it
> was a choice.
>
> Can anyone help shine some light on this decision?
>
> many thanks
>
> Andy Psarianos
>
> On 30 Jul 2004, at 18:38, Paul Sherfield wrote:
>
> > Hi Andy
> >
> > Yes it does look a little odd, but works well in practise, due to the
> > GCR
> > setting I think. This is the latest ISO wed coated icc, as of a few
> > months
> > ago?
> >
> > Worked very well for me when a client was given Euroscale coated v2 for
> > sheetfed images for a wed offset production with lots of neutral
> > consumer
> > electrical images. I was called in after the first printing!! We
> > changed the
> > Euroscale coated v2 to ISO web coated with good results when reprinted.
> >
> > Regards
> >
> > Paul Sherfield
> >
> >
> >
> >
> > The Missing Horse Consultancy Ltd
> >
> > Telephone: 01442 871752
> > Mobile: 07899 906385
> >
> >
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> > ECI-EN mailing list
> > ECI-EN(a)lists.transmedia.de
> > http://lists.transmedia.de/mailman/listinfo/eci-en
> >
>
> ______________________________________________________________________
> This email has been scanned by the MessageLabs Email Security System.
> For more information please visit http://www.messagelabs.com/email
> ______________________________________________________________________
>
> --__--__--
>
> Message: 2
> Cc: Andy Psarianos <andy(a)psarianos.com>
> From: Chris Murphy <lists(a)colorremedies.com>
> Subject: Re: [ECI-EN] RGB to CMYK with ISO web coated profile
> Date: Tue, 3 Aug 2004 15:03:16 -0600
> To: eci-en(a)lists.transmedia.de
> Reply-To: eci-en(a)lists.transmedia.de
>
> On Aug 3, 2004, at 2:46 PM, Andy Psarianos wrote:
> > RGB Adobe 1998:
> >
> > RGB 50,50,50 to "SWOP" CMYK = 70,64,63,62
> > (C highest and M and Y are similar values)
> >
> > RGB 50,50,50 to "ISO web coated" CMYK = 64,53,48,71
> > (C highest M in middle and Y lowest)
> >
> > I'm not saying SWOP is correct, but if I were to remove the black
> > separation it would appear grey wouldn't it? I don't believe the
> > values in the ISO web coated values would be neutral. If this is the
> > case, the question is why?
> >
> > I do understand that the lack of yellow in the dark greys could be
> > hidden by the heavy black, but I don't understand why this was done,
> > and why a more "conventional & balanced grey" was not chosen. Is it
> > simply that when printing shadows with equal amounts of m and y they
> > have a "yellowish hue" or is this an ink trapping issue?
>
> I see this frequently with inkjet printing. If the yellow ink is very
> saturated (pure) compared to the other inks, it will take less yellow
> to balance the blue produced by cyan and magenta. And some yellow inks
> can be fairly green, which would take more magenta to further offset
> that contamination in the yellow.
>
> Off hand I can't say what yellow ink hue is being used with ISO web
> coated, but this is probably what's going on. This is why color by the
> numbers doesn't work unless you know the inkset and the print behavior
> of the press/printer very well. CMYK numbers are ambiguous.
>
> Chris Murphy
> Color Remedies (TM)
> www.colorremedies.com/realworldcolor
> ---------------------------------------------------------
> Co-author "Real World Color Management"
> Published by PeachPit Press (ISBN 0-201-77340-6)
>
> --__--__--
>
> Message: 3
> Date: Wed, 04 Aug 2004 10:49:03 +0200
> From: Peter Kleinheider <pkleinheider(a)a1.net>
> Subject: Re: [ECI-EN] RGB to CMYK with ISO web coated profile
> To: eci-en(a)lists.transmedia.de
> <282E5EE1-E58E-11D8-A683-000393468A5E(a)psarianos.com>
> Reply-To: eci-en(a)lists.transmedia.de
>
> Andy
>
> When you do a relativ Colormetric Conversion from AdobeRGB to ISO Web
> Coated, a different way of gray-generation gets used as of perceptual.
>
> Since in a print run the yellow color is (usually) the last coler,
> Heidelberg (Profiles are done with Heidelberg PrintOpen) found that the
> yellow color is often reflecting and the color gets lighter the more
> yellow is on the sheet in a darkgray area. Therefor in the RelCol RI,
> the yellow color gets reduced a little bit more. Even at about 85%
> Gray, the values of yellow stall or drop when the color gets darker.
>
> When you separate using the Perceptive RI, you will find CMYK-Values
> that you would more consider as to be gray. But in real world pint
> production, you will not see much difference.
>
> Maybe Mr. Bestmann from Heidelberg cann explain that better.
>
> rgds
>
> Peter Kleinheider
>
> Am 03.08.2004 um 22:46 schrieb Andy Psarianos:
>
> > Paul,
> >
> > Thanks that's really helpful.
> >
> > Yes indeed I am talking about the latest release of the profile called
> > "ISO web coated"
> >
> >
> > For example if I convert the following values I get the following
> > results.
> >
> >
> > From RGB Adobe 1998:
> >
> > RGB 50,50,50 to "SWOP" CMYK = 70,64,63,62
> > (C highest and M and Y are similar values)
> >
> > RGB 50,50,50 to "ISO web coated" CMYK = 64,53,48,71
> > (C highest M in middle and Y lowest)
> >
> > I'm not saying SWOP is correct, but if I were to remove the black
> > separation it would appear grey wouldn't it? I don't believe the
> > values in the ISO web coated values would be neutral. If this is the
> > case, the question is why?
> >
> > I do understand that the lack of yellow in the dark greys could be
> > hidden by the heavy black, but I don't understand why this was done,
> > and why a more "conventional & balanced grey" was not chosen. Is it
> > simply that when printing shadows with equal amounts of m and y they
> > have a "yellowish hue" or is this an ink trapping issue?
> >
> > Overall, all tests I've done with the ISO web coated profile in
> > conversions results have been very good. I'm willing to accept that
> > these "unconventional values" in principle are OK, although I have
> > several sceptics here which I need to convince.
> >
> > I would like to know what the reason was for this choice, if indeed it
> > was a choice.
> >
> >
> > Can anyone help shine some light on this decision?
> >
> > many thanks
> >
> > Andy Psarianos
> >
>
> --__--__--
>
> Message: 4
> Date: Wed, 04 Aug 2004 09:55:26 +0100
> Subject: Re: [ECI-EN] RGB to CMYK with ISO web coated profile
> From: Paul Sherfield <paul(a)missinghorsecons.co.uk>
> To: <eci-en(a)lists.transmedia.de>
> CC: Andy Psarianos <andy(a)psarianos.com>
> Reply-To: eci-en(a)lists.transmedia.de
>
> Hi Andy
>
> It does look odd, but as Chris Murphy said the yellow can do strange things
> within a CMYK grey balance.
>
> I believe this GCR setting within the profile is causing the results you are
> seeing, reducing the yellow in a RGB to CMYK conversion to reduce the
> possibility of a yellow bias.
>
> The grey balance for ISO for the CMY is:
>
> Cyan Magenta Yellow
> Quarter tone 25% 19% 19%
>
> Mid tone 50% 40% 40%
>
> Three qu. tone 75% 46% 46%
>
> But this will not reflect the profile and any GCR that would be applied with
> a RGB to CMYK conversion.
>
> As you say the ISO profiles do work well, if the printers follow the
> standard printing conditions associated with each profile.
>
> Regards
>
> Paul
>
> The Missing Horse Consultancy Ltd
>
> Telephone: 01442 871752
> Mobile: 07899 906385
>
> --__--__--
>
> Message: 5
> Date: Wed, 04 Aug 2004 11:04:13 +0200
> From: Peter Kleinheider <pkleinheider(a)a1.net>
> Subject: Re: [ECI-EN] RGB to CMYK with ISO web coated profile
> To: eci-en(a)lists.transmedia.de
> Reply-To: eci-en(a)lists.transmedia.de
>
> Paul
>
> This is just a recomendation and does not take in concern any color
> cast of the paper.
>
> the issue is: if a printer is printing according to ISO 12647, then the
> colors will turn out to be gray on the prints (when doing a separation
> of AdobeRGB or ECI-RGB to ISO Web coated)
>
> Am 04.08.2004 um 10:55 schrieb Paul Sherfield:
>
> > The grey balance for ISO for the CMY is:
> >
> > Cyan Magenta Yellow
> > Quarter tone 25% 19% 19%
> >
> > Mid tone 50% 40% 40%
> >
> > Three qu. tone 75% 46% 46%
>
> Peter
>
> --__--__--
>
> _______________________________________________
> ECI-EN mailing list
> ECI-EN(a)lists.transmedia.de
> http://lists.transmedia.de/mailman/listinfo/eci-en
>
> End of ECI-EN Digest_______________________________________________
> ECI-EN mailing list
> ECI-EN(a)lists.transmedia.de
> http://lists.transmedia.de/mailman/listinfo/eci-en
--
John C. Hamilton
Input Technology Specialist
PMP Digital Melbourne
359 Plummer Street
Port Melbourne 3207
Victoria Australia
Ph 61 3 9245 1222
Fax 61 3 9646 6887
Email john.hamilton(a)pmpdigital.com.au
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I posted this on another list yesterday but below is an edited version
"Bob wrote:
The ECI profiles were produced using Heidelberg software and are well
rounded or averaged to produce a 'smooth' profile . There is some
debate to be had on the pros and cons of this rounding within certain
workflows.The ECI web coated ICC profile assumes 100% maximum black ,
which although not insurmountable, is not standard practice with most
of the PPA printers."
I responded with:
There are thousands of scanner operators and CMYK retouchers who
believe that in order to get a neutral colour your cyan should be
higher than your magneta and yellow AND the magenta and yellow should
be equal.
Every day these retouchers and scanners base their corrections around
this fairly fundamental belief, a belief wrote about by Dan Margulis
and many more I'm sure.
If you create an RGB file with R0 G0 B0 and proof it with the ECI
profile "IsoCoated" you will see that it reads cyan 87, magenta 86,
yellow 76 and black 99.
To all these retouchers this would suggest that it is going to come out
with a magenta bias. Therefore they would correct for that to make the
mag and yellow match. Many would also look at the black and say that 99
percent is too high and would not be happy at all about having to use
this profile.
If you compare it to "eurostandard coated" which ships with Photoshop
the same R0 G0 B0 converted to CMYK reads C95, M83, Y82 and K90. This
would be considered far more acceptable.
I don't have the Cromalin Eurostandard DP10 profile so I can't say what
thats like.
My point is that if Proof4Press comes out with a profile with dark
neutrals that are similar to the ECI profile then so be it but they had
better be ready to re-educate thousands of scanner operator and
retouchers and fight some pretty big battles on the way.
Regards,
Daniel."
I was talking about proof4press, a profile scheme someone is trying to
push through as a sort of generic space to use when you dont have
access to specific printer details (which in reality is nearly all the
time). Trying to achieve what the ISOcoated profile is supposed to be
used for.
Can someone who made the ISOcoated profile please tell me why the dark
neutrals don't match commonly held beliefs of neutrality and also why
the black was made using 100%, not 90 or 95%?
Thanks,
Daniel.
Mr. Bestmann,
You are right.
You was the man who explained in detail why we did not need gray balance
any more in the latest ISO 1247-2:2004 descriptions.
However,
I don't agree that we would have the right to treat you as the "bad" guy.
In this case you was the source of the information and the messenger.
In the past we did not have the tools nor the complete knowledge to drive
our presses without gray balance information. The members to this list know
how to value the data of nowadays spectral meters.
However, for a long time printers in less sophisticated environments were
(and still are) are forced to use the old technologies to run their old
presses, even without a densitometer.
It's good to see that you are continuously offering your help to apply
these new standards.
With tight margins and shared responsibilities between designers, prepress and
printers we need the standards to make the arrangements between all members
in the complete chain, between customer and delivered product.
Any of your "corrections" or additions to use the new standards in our
production is highly appreciated. Even if we have to redefine our goals or
(as a consultant) have to modify our presentations!
So continue to act the way you do. In my opinion you (and your colleges in
Heidelberg, ECI and MedienStandard Druck) show a "good guy" attitude.
regards, Henk
.
-----------------------------------------------------------------------------------------
Henk Gianotten, Prins Hendriklaan 58 3761 DW Soest, Netherlands
Tel. + Fax: +31 (0)35 60 122 06 e-mail: henk(a)gianotten.com
-----------------------------------------------------------------------------------------