Hi Mike, all, from Fogra point of view we don’t think users will understand substrate corrected data sets. Thats why there won’t be such a thing (from us). What we do is the same but from buyers point of view. We ask them to decide at the beginning of a side-by-side reproduction (e.g. against GraColUncoated) is used or a media relative (more relaxed) reproduction (since colour memory is not so good but adaption). So the media relative calculation only kicks in the background when doing the analysis (conformance evaluation). All this is outlined in ProcessStandard Digital - PSD. regards Andy Follow us on Twitter: English channel: https://twitter.com/fogra_org <https://twitter.com/fogra_org> Deutscher Kanal: https://twitter.com/fogra_de <https://twitter.com/fogra_de> Dr.-Ing. Andreas Kraushaar Dept. Prepress Fogra Graphic Technology Research Association Streitfeldstrasse 19 81673 Munich, Germany Telefon: +49 89. 431 82 - 335 Telefax: +49 89. 431 82 - 100 E-mail: kraushaar@fogra.org <mailto:kraushaar@fogra.org> Internet: www.fogra.org <http://www.fogra.org/> ----------------------------------------------------------------- This e-mail message may contain confidential and/or privileged information. If you are not an addressee or otherwise authorized to receive this message, you should not use, copy, disclose or take any action based on this e-mail or any information contained in the message. If you have received this material in error, please advise the sender immediately by reply e-mail and delete this message. Managing Director: Dr. Eduard Neufeld | Registered Office: Munich | Register of Associations: VR 4909
On 18 Jun 2015, at 17:34, Hanno Hoffstadt <Hanno.Hoffstadt@gmgcolor.com> wrote:
I'd say that standard reference data still are the basis for substrate calculated data. The only extra information needed is the assumed substrate white (CIELAB).
So my vision is to print that LAB along with the control strip of the proof, and anyone can check the proof control strip after entering these Lab numbers.
One could even imagine that this user interaction is not needed: The paper white simulation which is measured could be compared against the standard, and if different enough, could directly be used to substrate-correct the aim values for the whole strip. Maybe informing the user that a custom white has been detected, OK to proceed?
E.g. ISO 12647-2:2013 usually has a tolerance of 2 b* units for the PS (= printing substrate) categories, and explicitly states in the preamble that the standard can be applied to substrates outside if one uses a substrate correction method like the informative one given in Annex B and other standards.
(A minor detail is the black XYZ needed in the formula, but this could be derived starting from the 100 K value given in the standard.)
Hanno
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Message: 3 Date: Wed, 17 Jun 2015 12:19:37 -0500 From: Mike Stewart <mstewart@embassygraphics.com<mailto:mstewart@embassygraphics.com>> To: colorsync-users <colorsync-users@lists.apple.com<mailto:colorsync-users@lists.apple.com>> Subject: dealing with printers Message-ID: <CAFB95os3sXyi6gH9+ZXKvJxUcnchKLpP8GfVE=dAHAi2spFySA@mail.gmail.com<mailto:CAFB95os3sXyi6gH9+ZXKvJxUcnchKLpP8GfVE=dAHAi2spFySA@mail.gmail.com>> Content-Type: text/plain; charset=UTF-8
Now that we are moving to Substrate Calculated Data sets based on paper white; how on earth do we communicate this to printers. Before OBA's we had GRACoL, Fogra47 - just to name a few. We would colour manage our proofs to GRACoL or Fogra47 (or some print specification), place an Idealliance colour bar on each proof and the customer/printer could measure the colour bar to see if we were in compliance or not to the particular specification.
Now we start from GRACoL Uncoated 2013, change the Paper White values, create a new Data Set and proof to the new data set. Our colour bar on each proof now becomes useless as it will never match to the original GRACoL Uncoated 2013. How do we communicate this to a printer in Asia. How can they now trust our proofs. Do we give them a small single row Press Type Colour Bar that prints within the job itself and also give the printer the specs. for that colour bar. If so, what are the specs. of that colour bar (C,M,Y,K,R,G,B, grey balance swatches, etc). Data for that file would have to be colorimetric and not solid ink and dot gain values I'm guessing.
Thanks Mike Stewart
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