7:44 a.m.
Hello Paul
It shouldn't be too difficult to make also 40% and 80% patches. I have
myself made it so that I created 3-colour profiles from Fogra data, looked
what Lab e.g. 40 black gives and then look from the 3-colour profile what
CMY values this Lab-values of black correspond.
And actually Eci/bvdm CMY 50% correspond to 45/36/33 for ISOcoated. If we
would force cyan to stay 50% we would end up with something like C50%, M42%,
Y37%, which would correspond to K56%
I have already tested Eci/bvdm gray control strip and our own with same
principle on test printing and it works very well.
BR Jouni Marttila
-----Original Message-----
From: eci-en-admin(a)lists.transmedia.de
[mailto:eci-en-admin@lists.transmedia.de] On Behalf Of Paul Sherfield
Sent: 22. joulukuuta 2005 19:50
To: eci-en(a)lists.transmedia.de
Subject: [ECI-EN] Re: ECI/bvbm Grey Control Strip (M) Fogra 27
Hi
Is there ant English documentation on the use of this control strip?
Also can I ask why the 50%, and 70% patches were chosen over
the 40% (quoted as 50% 40% 40%) and 80% which are highlighted
in the Altona documentation?
And where can this chart be downloaded?
Many thanks
Paul Sherfield
The Missing Horse Consultancy Ltd
Telephone: 01442 871752
Mobile: 07899 906385
http://www.missinghorsecons.co.uk
Apple Solutions Expert-Print & Publishing
This email and any attachments may be confidential and are
intended solely for the use of addressee. If you are not the
intended recipient of this message, any disclosure, copying or
other distribution is strictly prohibited and may be unlawful.
If you have received this message in error, please notify the
sender and delete all copies from your system. Email may be
susceptible to data corruption, interception and unauthorised
amendment. We do not accept liability for any such corruption,
interception or amendment or the consequences thereof. We do
not accept liability for any action or inaction by the
recipient as a result of advice or information contained
within this email.
_______________________________________________
ECI-EN mailing list
ECI-EN(a)lists.transmedia.de
http://lists.transmedia.de/mailman/listinfo/eci>-en
10:03 a.m.
New subject: ECI/bvbm Grey Control Strip (M) Fogra 27
Hello Paul et al,
As Olaf mentioned already the English documentation will be available
soon. It describes exactly how to calculate the CMY values based on
the CIELAB values of the respective black ink patch taken from the
characterization data (absolute colorimetric color conversion).
With regard to your question about the selected black ink percentages:
We wanted to add a quarter tone and a three quarter tone to the 50%
patch. 40 percent sits too close to 50 and 80 is too high.
Of course it would have been possible to add further patches with
percentages between 0 and 100 %. But as all of us know space is very
limited and paper cost is another reason to limit the strip length.
The versions 'L' and 'M' contain patches to capture the dot gain
curves plus trapping. The strips shall not exceed the width ('M') and
height ('L') of A4 pages, letter respectively. Otherwise it would not
be possible to place the strips on typical press sheet signatures. In
order to enable effective measurements by spectrophotometers such as
the Heidelberg ImageControl the patches have to be not smaller than 6
by 5.5 millimeters.
Best regards,
Florian
Am 23.12.2005 um 07:44 schrieb Marttila Jouni:
Hello Paul
It shouldn't be too difficult to make also 40% and 80% patches. I have
myself made it so that I created 3-colour profiles from Fogra data,
looked
what Lab e.g. 40 black gives and then look from the 3-colour
profile what
CMY values this Lab-values of black correspond.
And actually Eci/bvdm CMY 50% correspond to 45/36/33 for ISOcoated.
If we
would force cyan to stay 50% we would end up with something like
C50%, M42%,
Y37%, which would correspond to K56%
I have already tested Eci/bvdm gray control strip and our own with
same
principle on test printing and it works very well.
BR Jouni Marttila
--
Florian Suessl, Director Technology
MetaDesign AG, Leibnizstrasse 65, 10629 Berlin
+49 30 59 00 54 246, fax +49 30 59 00 54 114
fsuessl(a)metadesign.de, http://www.metadesign.de, www.metaprintcheck.de
-----Original Message-----
From: eci-en-admin(a)lists.transmedia.de
[mailto:eci-en-admin@lists.transmedia.de] On Behalf Of Paul Sherfield
Sent: 22. joulukuuta 2005 19:50
To: eci-en(a)lists.transmedia.de
Subject: [ECI-EN] Re: ECI/bvbm Grey Control Strip (M) Fogra 27
Hi
Is there ant English documentation on the use of this control strip?
Also can I ask why the 50%, and 70% patches were chosen over
the 40% (quoted as 50% 40% 40%) and 80% which are highlighted
in the Altona documentation?
And where can this chart be downloaded?
Many thanks
Paul Sherfield
The Missing Horse Consultancy Ltd
Telephone: 01442 871752
Mobile: 07899 906385
http://www.missinghorsecons.co.uk
Apple Solutions Expert-Print & Publishing
This email and any attachments may be confidential and are
intended solely for the use of addressee. If you are not the
intended recipient of this message, any disclosure, copying or
other distribution is strictly prohibited and may be unlawful.
If you have received this message in error, please notify the
sender and delete all copies from your system. Email may be
susceptible to data corruption, interception and unauthorised
amendment. We do not accept liability for any such corruption,
interception or amendment or the consequences thereof. We do
not accept liability for any action or inaction by the
recipient as a result of advice or information contained
within this email.
_______________________________________________
ECI-EN mailing list
ECI-EN(a)lists.transmedia.de
http://lists.transmedia.de/mailman/listinfo/eci>-en
_______________________________________________
ECI-EN mailing list
ECI-EN(a)lists.transmedia.de
http://lists.transmedia.de/mailman/listinfo/eci-en
3:51 p.m.
New subject: ECI/bvbm Grey Control Strip (M) Fogra 27
And actually Eci/bvdm CMY 50% correspond to 45/36/33
for ISOcoated.
BR Jouni Marttila
45/36/33? Wow, so much for "portability" between SWOP-kind of separations at
50/40/40 and Europe, if that's what ISO-coated gives. Or am I comparing
apples with oranges?
Roger Breton | Laval, Canada | graxx(a)videotron.ca
http://pages.infinit.net/graxx
4:37 p.m.
New subject: ECI/bvbm Grey Control Strip (M) Fogra 27
Hi Roger
Yes, I am confused by these grey balance figures on this Control Strip, (and
just as I thought I was beginning to understand this and the GRACol work!)
In the current ISO 12647-2:2004 in Annex C (Informative), the CMYK values
for use in Grey balance patches are:
Quarter tone 25C 19M 19Y
Mid tone 50C 40M 40Y
Three
Quarter tone 74C 64M 64Y
So are the new Fogra figures more accurate and replace these (Informative)
figures in the ISO standard.
Happy Christmas
Paul Sherfield
The Missing Horse Consultancy Ltd
Telephone: 01442 871752
Mobile: 07899 906385
http://www.missinghorsecons.co.uk
Apple Solutions Expert-Print & Publishing
This email and any attachments may be confidential and are intended solely
for the use of addressee. If you are not the intended recipient of this
message, any disclosure, copying or other distribution is strictly
prohibited and may be unlawful. If you have received this message in error,
please notify the sender and delete all copies from your system. Email may
be susceptible to data corruption, interception and unauthorised amendment.
We do not accept liability for any such corruption, interception or
amendment or the consequences thereof. We do not accept liability for any
action or inaction by the recipient as a result of advice or information
contained within this email.
4:55 p.m.
New subject: ECI/bvbm Grey Control Strip (M) Fogra 27
Hi again
Just do some testing re the Grey balance for ISO coated data set 27.
The figures quoted for the control strip are accurate.
The Alwan Color Pursuit CM workflow tool shows and Delta e 94,(better for
comparing greys!) of 1.0 for the control strip CMY figures and an Delta e
of 6.2 for the ISO 12647-2:2004 informative figures.
So where did these original ISO figures come from, looking interesting in
relation to GRACol v7 as Roger pointed out.
Regards
Paul Sherfield
The Missing Horse Consultancy Ltd
Telephone: 01442 871752
Mobile: 07899 906385
http://www.missinghorsecons.co.uk
Apple Solutions Expert-Print & Publishing
This email and any attachments may be confidential and are intended solely
for the use of addressee. If you are not the intended recipient of this
message, any disclosure, copying or other distribution is strictly
prohibited and may be unlawful. If you have received this message in error,
please notify the sender and delete all copies from your system. Email may
be susceptible to data corruption, interception and unauthorised amendment.
We do not accept liability for any such corruption, interception or
amendment or the consequences thereof. We do not accept liability for any
action or inaction by the recipient as a result of advice or information
contained within this email.
5:45 p.m.
New subject: ECI/bvbm Grey Control Strip (M) Fogra 27
Hi Paul,
The reason for the differences between the GRACoL and ECI/bvdm gray
patches is the different approach. GRACoL starts with fixed CMY-
values. ECI/bvdm follow the second 'practical definition for grey'
published in the current ISO 12647-2:2004 (Annex C) and calculate CMY
values per printing condition:
There are two practical definitions for grey that are
sometimes in
conflict:
a) a colour having the same a* and b* CIELAB values as the print
substrate;
b) a colour having the same a* and b* CIELAB values as a half-tone
tint of similar L* value printed with
black ink.
If you wish to double check here is a step by step description (as
described in the German documentation coming with the ECI/bvdm Gray
Control Strip which will be available in English soon):
[1] Starting point is the respective FOGRA characterization data,
e.g. FOGRA27
(as there are no ISO values for tints)
[2] search for the black only patches with the tone values 30, 50, 70 %
in the case of FOGRA27 these values are:
L* a* b*
k30 77,02 0,07 -3,69
k50 62,69 -0,04 -3,41
k70 46,44 0,02 -2,61
[3] color convert the CIELAB values to CMY (without K)
e.g. by GretagMacbeth ColorPicker:
- setting (in our example for FOGRA27):
- profile: ISOcoated.icc
- Rendering Intent: absolute colorimetric
- set calculated 'K' value to zero and deselect 'K'
- press 'minimize dE' (maybe the button text is slightly different)
- note the CMY values
in the case of FOGRA27, ISOcoated.icc respectively these values are:
C M Y
g30 27 20 18
g50 45 36 33
g70 65 57 50
Hope this helps to answer your questions.
Best regards,
Florian
Am 23.12.2005 um 16:55 schrieb Paul Sherfield:
Hi again
Just do some testing re the Grey balance for ISO coated data set 27.
The figures quoted for the control strip are accurate.
The Alwan Color Pursuit CM workflow tool shows and Delta e 94,
(better for
comparing greys!) of 1.0 for the control strip CMY figures and an
Delta e
of 6.2 for the ISO 12647-2:2004 informative figures.
So where did these original ISO figures come from, looking
interesting in
relation to GRACol v7 as Roger pointed out.
Regards
Paul Sherfield
The Missing Horse Consultancy Ltd
Telephone: 01442 871752
Mobile: 07899 906385
http://www.missinghorsecons.co.uk
Apple Solutions Expert-Print & Publishing
This email and any attachments may be confidential and are intended
solely
for the use of addressee. If you are not the intended recipient of
this
message, any disclosure, copying or other distribution is strictly
prohibited and may be unlawful. If you have received this message
in error,
please notify the sender and delete all copies from your system.
Email may
be susceptible to data corruption, interception and unauthorised
amendment.
We do not accept liability for any such corruption, interception or
amendment or the consequences thereof. We do not accept liability
for any
action or inaction by the recipient as a result of advice or
information
contained within this email.
_______________________________________________
ECI-EN mailing list
ECI-EN(a)lists.transmedia.de
http://lists.transmedia.de/mailman/listinfo/eci-en
--
Florian Suessl, Director Technology
MetaDesign AG, Leibnizstrasse 65, 10629 Berlin
+49 30 59 00 54 246, fax +49 30 59 00 54 114
fsuessl(a)metadesign.de, http://www.metadesign.de, www.metaprintcheck.de
6:05 p.m.
New subject: ECI/bvbm Grey Control Strip (M) Fogra 27
> There are two practical definitions for grey that
are sometimes in
> conflict:
> a) a colour having the same a* and b* CIELAB values as the print
> substrate;
> b) a colour having the same a* and b* CIELAB values as a half-tone
> tint of similar L* value printed with
> black ink.
So Florian,
Which way is ISO-coated build? CMY grays relative to the substrate or
similar to 50K?
Mfg,
Roger Breton | Laval, Canada | graxx(a)videotron.ca
http://pages.infinit.net/graxx
6:32 p.m.
New subject: ECI/bvbm Grey Control Strip (M) Fogra 27
Roger,
The ECI/bvdm Gray Control Strip was made according to definition b):
>> b) a colour having the same a* and b* CIELAB
values as a half-tone
>> tint of similar L* value printed with
>> black ink.
Regarding the characterization data FOGRA27 and the respective
profile ISOcoated.icc:
The reference prints were made following the ISO 12647-2:2004
specifications for
1. solids (CIELAB values),
2. dot gain curves and
3. mid tone spread.
I.o.w.
The ECI/bvdm Gray Control Strip closes the loop beeing a helpful mean
for the printer to match the reference print. The idea behind this
approach is, that ...
(1) clients should be able to see realistic digital proofs that can
be reached in the press run (prepress-data and digital proofs created
with ICC-profiles that are based on real world reference prints)
(2) pressmen should receive data and proofs they can reach easily
match colorwise by adjusting their printing process to the same ISO
conditions.
BR,
Florian
Am 23.12.2005 um 18:05 schrieb Roger Breton:
>>> There are two practical definitions for grey that are sometimes in
>>> conflict:
>>> a) a colour having the same a* and b* CIELAB values as the print
>>> substrate;
>> b) a colour having the same a* and b* CIELAB
values as a half-tone
>> tint of similar L* value printed with
>> black ink.
>
> So Florian,
>
> Which way is ISO-coated build? CMY grays relative to the substrate or
> similar to 50K?
>
> Mfg,
>
> Roger Breton | Laval, Canada | graxx(a)videotron.ca
> http://pages.infinit.net/graxx
>
>
> _______________________________________________
> ECI-EN mailing list
> ECI-EN(a)lists.transmedia.de
> http://lists.transmedia.de/mailman/listinfo/eci-en
>
--
Florian Suessl, Director Technology
MetaDesign AG, Leibnizstrasse 65, 10629 Berlin
+49 30 59 00 54 246, fax +49 30 59 00 54 114
fsuessl(a)metadesign.de, http://www.metadesign.de, www.metaprintcheck.de
7:19 p.m.
New subject: ECI/bvbm Grey Control Strip (M) Fogra 27
The ECI/bvdm Gray Control Strip was made according to
definition b):
>>> b) a colour having the same a* and b* CIELAB values as a half-tone
>>> tint of similar L* value printed with
>>> black ink.
Florian,
Das ist sehr gut! But it is different from Gracol's idea. Still, I prefer to
match the Lab of the 50% black halftone dot. Personally, I think it makes
more sense. The goal I am pushing for is to have the same Status-T density
readings for 50c40m40y (0.60 on the red filter, 0.60 on the green filter and
0.60 on the yellow filter) as the Status-T density reading for 50k (0.60
Visual).
Is that practice widespread in Europe?
Roger Breton | Laval, Canada | graxx(a)videotron.ca
http://pages.infinit.net/graxx
6712
days inactive
6712
days old
eci-en@lists.callassoftware.com
8 comments
4 participants
participants (4)
-
Florian Süßl -
Marttila Jouni -
Paul Sherfield -
Roger Breton