Mike, Not really done it with your equipment but for inkjet printers I have a shareware tool that comes close to your requirements and I could add data of your papers to it. http://www.pigment-print.com/spectralplots/spectrumviz_1.htm Right now it groups (inkjet) papers on other properties but shows the paper white spectral plots (including OBA effect) of each paper so one can overlay the spectral plots to see whether they share the same spectral plot or not. That tells more about the paper white than just the OBA content. It does not tell how ink behaves per paper which is another property of the paper c.q. coating. There is already a small group of offset papers available in the list of >700 papers. On request of a UK based printing company. Adding 150 papers would be possible. I measure the paper with iShare and an i1Pro without a UVcut filter. I guess you need maps with identical spectral plots and their average Lab numbers or the compatible printer profile as the group name. Maybe another SpectrumViz copy for non-inkjet papers gloss/matte.coated/uncoated and within the four maps identical spectral plots in one group. I guess it would be usable despite the different spectrometers we use. It would still be a standalone app made with one spectrometer. I am a bit surprised to see Lab b -13 to -15 quoted in this thread, -11 is about the highest I have measured so far but 95% are inkjet papers in my case. Could be that my i1Pro does not create a similar OBA effect. Met vriendelijke groet, Ernst Dinkla Dinkla Grafische Techniek Quad, piëzografie, giclée www.pigment-print.com On Wed, Jun 17, 2015 at 7:06 PM, Mike Stewart <mstewart@embassygraphics.com> wrote:
As I've mentioned before. we are a pre-press provider for publishers and printers worldwide. We use an Indigo Press as a proofer and 95% of the time print/proof is on the actual press stock. This paper is mostly supplied to us by the printer themselves. As I look into our press room I would say that I probably have about 150 different papers; three quarters of which are uncoated stocks heavily laden with OBA's. Using the i1Pro2 in M1 mode I have measured all the papers.
I cannot possibly have 150 different colour managed Hot Folders with individual colour tables based on each stock we proof on. (It would be a nightmare to build and control). I want to group papers into groups based on LAB M1 measurements. Example: 94, 1.0, -9 might be one group. My colour managed Hot Folder would have a colour set up created from 94, 1.0, -9 and I'm wondering if there are any "rule of thumb" tolerances I could use for my groups. Say Group 1 has been set up with 94, 1.0, -9 and my tolerance is L+/- 2, *a +/- 1, *b+/- 2. I could now group all papers that fall within those specs. I realize colour would not be an exact match for each sheet; but should be close enough to allow a printer to "match" the proof.
Has anyone done this and does anyone know if my tolerances are out of whack? My +/- 2 could become quite a large tolerance if ..
94, 1.0, -9 92, -1.0 -7 Is this to large of a gap?
Any help would be appreciated. Mike Stewart _______________________________________________ Do not post admin requests to the list. They will be ignored. Colorsync-users mailing list (Colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription:
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