1:21 a.m.
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
10:35 a.m.
New subject: RGB to CMYK ISO web coated profile
Belinda Beckinsale wrote
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.
This is a major issue, ISO profiles are aimed it a standard printing
condition, SID, TVI and all that! If you have other 'unknown' CMYK files do
you know what printing conditions they are for?
Do the advertisers have a CMYK spec to meet, set by the publishers, if so is
this ISO?
If you are getting a lot of mystery CMYK files or CMYK profiled to other
printing conditions they are unlikely to print correctly using ISO
standards.
You need to use workflow tools, such us CMYK Optimiser to change the PDF's
via a devise link profile to the CMYK (ISO?) you need.
Regards
Paul Sherfield
The Missing Horse Consultancy Ltd
Telephone: 01442 871752
Mobile: 07899 906385
5:54 p.m.
New subject: RGB to CMYK ISO web coated profile
On Aug 5, 2004, at 5:21 PM, Belinda Beckinsale wrote:
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?
The problem is being overstated. Downloading the "ISOwebcoated.icc"
profile, Paper type 3, gloss coated web (LWC), 150 lpi (60/cm),
FOGRA28L, from the ECI web site, I get the following conversions for
L*50
SWOPv2, RelCol+BPC, 55, 46, 46, 11
ISOWeb, RelCol+BPC, 44, 35, 34, 28
ISOWeb, Perceptual 41, 32, 32, 23
For L*25 I get:
SWOPv2, RelCol+BPC, 68, 62, 61, 51
ISOWeb, RelCol+BPC, 60, 49, 46, 62
ISOWeb, Perceptual 56, 45, 43, 52
Now when I take 100% yellow, and ask the SWOP v2 profile, and ISO Web
Coated profile what the LAB values are (AbsCol),
I get:
SWOP v2 84, -6, 83
ISO Web 86, -3, 93
That is a huge difference numerically. Simple delta E is 10. Delta E
2000 predicts delta E 3 because it does a better job of understanding
humans aren't that sensitive to saturated colors, in particular yellow.
Still a real delta E of 3 is noticeable, therefore it makes sense the
separation is going to be different because an integral primary is
different. The other primaries are no where near this different.
So the answers to the question:
1. There is no traditional gray balance.
2. If a printer is receiving jobs with different gray balance, one of
them is wrong, and he will have to either make the right one look right
(good), the wrong one look good (bad), or compromise (maybe good or bad
depending on context).
Moral of the story is that your separations, including gray balance
need to be targeted for the final output process. That means one set of
separations for U.S. publications and another set for Euro. You need
them anyway because the TVI difference is more radical than the 4 point
discrepancy in shadow gray balance for yellow compared to magenta.
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?
If the measurement data is correct for the printing conditions being
used, even irrespective of paper white, then GCR is not going to
dramatically affect this if the profile is built correctly. The profile
building application should build the proper CMY balance to produce a
neutral regardless of paper white.
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.
I don't see how this could work. There are standard printing conditions
already, and profiles based on their measurement data are gray
balanced. That each one has different gray balance is due to different
inksets being used, primarily, as in this example.
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.
There are two possibilities. A dumb scanner setup should be set
conservatively so you aren't clipping shadow or highlight detail. This
is the one size fits all approach, constantly scanning with the same
settings. Yes you do lose a few levels with this strategy. Someone is
going to have to set white and black later, in Photoshop for example.
So there is no free lunch here unless you have more skilled Photoshop
operators than you do scanner operators (that is the trend).
The other approach is to set black point and white point in the scanner
software on an image by image basis. This maximizes the ability of the
scanner better, but clearly is more time consuming up front.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
---------------------------------------------------------
Co-author "Real World Color Management"
Published by PeachPit Press (ISBN 0-201-77340-6)
11:27 p.m.
New subject: European colour Scale versus ISO Scale
I believe that it is commonly felt that the profile for ISO Web coated
gives a good result for those who print to the ISO 12647-2 spec, which
calls for Ink that conforms to another ISO number (ISO 2846-1 I
believe).
I saw that there was a point raised earlier making a reference to the
proof4press specification (PPA) which is based on a Dupont "curve" for
one of their devices called Euro Offset DP10. Calibrated proofs created
by Dupont devices with this curve are accepted by Magazine Publishers
in the UK as a de-facto proofing standard.
In conversations with web-offset printers in the UK, most claim to use
the ISO ink sets, which makes it possible for them to print to the ISO
12637-2 spec. I have seen a report created by an "independant" saying
that this Dupont "curve" is a good representation of ISO 12647-2, but I
don't believe it. I have a suspicion that this Dupont "curve" is based
on a different ink set called "European Colour Scale" (DIN 16539 I
believe), and not the ISO Ink set.
Does anybody know what ink set (or printing condition) the Dupont "Euro
Offset DP10" curve tries to represent ?
Are Inks based on Euroscale still in commercial use today?
Many thanks,
Andy Psarianos
I'm interested in knowing if any one
On 9 Aug 2004, at 16:54, Chris Murphy wrote:
On Aug 5, 2004, at 5:21 PM, Belinda Beckinsale wrote:
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
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______________________________________________________________________
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?
The problem is being overstated. Downloading the "ISOwebcoated.icc"
profile, Paper type 3, gloss coated web (LWC), 150 lpi (60/cm),
FOGRA28L, from the ECI web site, I get the following conversions for
L*50
SWOPv2, RelCol+BPC, 55, 46, 46, 11
ISOWeb, RelCol+BPC, 44, 35, 34, 28
ISOWeb, Perceptual 41, 32, 32, 23
For L*25 I get:
SWOPv2, RelCol+BPC, 68, 62, 61, 51
ISOWeb, RelCol+BPC, 60, 49, 46, 62
ISOWeb, Perceptual 56, 45, 43, 52
Now when I take 100% yellow, and ask the SWOP v2 profile, and ISO Web
Coated profile what the LAB values are (AbsCol),
I get:
SWOP v2 84, -6, 83
ISO Web 86, -3, 93
That is a huge difference numerically. Simple delta E is 10. Delta E
2000 predicts delta E 3 because it does a better job of understanding
humans aren't that sensitive to saturated colors, in particular
yellow. Still a real delta E of 3 is noticeable, therefore it makes
sense the separation is going to be different because an integral
primary is different. The other primaries are no where near this
different.
So the answers to the question:
1. There is no traditional gray balance.
2. If a printer is receiving jobs with different gray balance, one of
them is wrong, and he will have to either make the right one look
right (good), the wrong one look good (bad), or compromise (maybe good
or bad depending on context).
Moral of the story is that your separations, including gray balance
need to be targeted for the final output process. That means one set
of separations for U.S. publications and another set for Euro. You
need them anyway because the TVI difference is more radical than the 4
point discrepancy in shadow gray balance for yellow compared to
magenta.
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?
If the measurement data is correct for the printing conditions being
used, even irrespective of paper white, then GCR is not going to
dramatically affect this if the profile is built correctly. The
profile building application should build the proper CMY balance to
produce a neutral regardless of paper white.
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.
I don't see how this could work. There are standard printing
conditions already, and profiles based on their measurement data are
gray balanced. That each one has different gray balance is due to
different inksets being used, primarily, as in this example.
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.
There are two possibilities. A dumb scanner setup should be set
conservatively so you aren't clipping shadow or highlight detail. This
is the one size fits all approach, constantly scanning with the same
settings. Yes you do lose a few levels with this strategy. Someone is
going to have to set white and black later, in Photoshop for example.
So there is no free lunch here unless you have more skilled Photoshop
operators than you do scanner operators (that is the trend).
The other approach is to set black point and white point in the
scanner software on an image by image basis. This maximizes the
ability of the scanner better, but clearly is more time consuming up
front.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
---------------------------------------------------------
Co-author "Real World Color Management"
Published by PeachPit Press (ISBN 0-201-77340-6)
_______________________________________________
ECI-EN mailing list
ECI-EN(a)lists.transmedia.de
http://lists.transmedia.de/mailman/listinfo/eci-en
12:08 a.m.
New subject: European colour Scale versus ISO Scale
At 22:27 9-8-2004 +0100, you wrote:
I believe that it is commonly felt that the profile for
ISO Web coated
gives a good result for those who print to the ISO 12647-2 spec, which
calls for Ink that conforms to another ISO number (ISO 2846-1 I believe).
I saw that there was a point raised earlier making a reference to the
proof4press specification (PPA) which is based on a Dupont "curve" for one
of their devices called Euro Offset DP10. Calibrated proofs created by
Dupont devices with this curve are accepted by Magazine Publishers in the
UK as a de-facto proofing standard.
In conversations with web-offset printers in the UK, most claim to use the
ISO ink sets, which makes it possible for them to print to the ISO 12637-2
spec. I have seen a report created by an "independant" saying that this
Dupont "curve" is a good representation of ISO 12647-2, but I don't
believe it. I have a suspicion that this Dupont "curve" is based on a
different ink set called "European Colour Scale" (DIN 16539 I believe),
and not the ISO Ink set.
Does anybody know what ink set (or printing condition) the Dupont "Euro
Offset DP10" curve tries to represent ?
Are Inks based on Euroscale still in commercial use today?
There seems to be some confusion at the ink producers and vendors.
"EuroScale" or "Euroskala" does not exist anymore.
We left those old Din-standards and ink producers will be able to deliver
ISO 2648-1 inks. It's an international standard and in spite of the fact
that a lot of Americans seem to believe that ISO 2648-1 is linked to
"Euroscale" it's not.
In the latest NPES Specs CGATS Recommended Practise, the Color
Characterisation Data sets 2846-1 is clearly described as the ink standards
to be used.
Gracol, SWOP and SNAP define the use of ISO 2846-1 and ISO 2846-2 (coldset)
standards.
Larry Walter of Fuji wrote on that subject several interesting articles.
And our color guru David McDowell of Kodak (and NPES) recently explained
why this is so important for all printers around the world.
The problem however, seems that the ink researchers and technicians know
very well what to do.
Ink marketing managers sometimes lack some knowledge and still call those
new inks based on old marketing names.
In a recent survey we found out that most suppliers and producers can
deliver inks based on ISO 2846-1 and ISO 2846-2 but the sales departments
still called those inks "EuroScale". That's wrong.
In Germany a handy booklet "CMYKhandinhandbook" was published by a prepress
service SatzInform provider in Berlin. The color scales were printed based
on ISO 12647-2 print standards and ISO 2846-1 ink standard. In the masthead
the ink producer is mentioned and the name of the inks too.
The proudly call them the new "EuroScale" inks. That's wrong. Any ISO
2846-1 compliant ink cannot be named "EuroScale".
So forget the part "Euro" in your ink. The only organization which may use
the name Euro Offset Standard seems Brunner Systems in Switzerland. The
have a kind of copyright for the name "EuroOffset".
Bur EuroScale European Scale or EuroSkala are non-existent.
Dupont has to rename their internal standards too.
And better explain which version of ISO 12647-2 they comply.
The old version of 1997 or the 2004 version, now in use by BVDM, Fogra and ECI.
regards, Henk
7203
days inactive
7207
days old
eci-en@lists.callassoftware.com
4 comments
5 participants
participants (5)
-
Andy Psarianos -
Belinda Beckinsale -
Chris Murphy -
Henk Gianotten -
Paul Sherfield