From Bill Atkinson, re: "Within The Stone"
From Bill Atkinson, re: "Within The Stone"
- Subject: From Bill Atkinson, re: "Within The Stone"
- From: Marco Ugolini <email@hidden>
- Date: Wed, 15 Oct 2008 17:10:21 -0700
- Thread-topic: From Bill Atkinson, re: "Within The Stone"
Dear friends at the ColorSync forum,
Aware that it may hold interest for others besides myself following a recent
ColorSync thread that touched upon the subject, and with Bill Atkinson's
kind permission, I am posting on this forum his reply to an inquiry of mine
regarding his book "Within The Stone" and the techniques used to print it.
My thanks to Bill for his extensive and helpful answers.
Marco Ugolini
> ------ Forwarded Message
> From: Bill Atkinson
> Date: Mon, 13 Oct 2008 12:19:41 -0700
> Subject: Re: About "Within The Stone"
> Dear Marco,
>
> Thanks for your interest in Vanfu's high quality printing of my book "Within
> the Stone". I have not been tracking the ColorSync forums and have not read
> the discussion about my experience with Vanfu. I assure you that the numbers
> I report in my pdf are from actual measurements and have not been fudged.
> Perhaps you can forward this email to the forum.
>
> I would be pleased to see more printers using color management to achieve
> higher quality at lower cost.
>
> To save me time scrounging up and preparing JPEGs to email to you, please open
> my pdf "Making Within the Stone" and allow me to refer to a few pages of that
> pdf. It can be downloaded from
> <http://homepage.mac.com/billatkinson/FileSharing2.html>.
>
> I believe the high quality of printing we achieved at Vanfu was a product of
> several factors, and I will share these with you to help you reproduce my good
> results.
>
> We printed the book on a normal four color Heidelberg Speedmaster CD102-4
> sheet fed press. A second one-color press was used to apply spot varnish.
>
> The biggest improvement in gamut came from abandoning SWOP and mapping colors
> directly to the press profile. This makes sense because SWOP is a
> lowest-common denominator designed so that any press can be dumbed down to
> meet it. Any particular combination of press, paper, ink and printing
> conditions can achieve considerably higher gamut even with standard inks.
>
> Using color management allowed us to always run the press at its optimum sweet
> spot densities (widest gamut) and never deviate from those to make color
> adjustments on press. We also saved a great deal of money, materials and
> press time by printing to numbers and eliminating all trial and error during
> make ready. As soon as the sweet spot densities were reached we were printing
> final copy. The once-only color management research took some time up front,
> but when we started printing the 180 page book the press time was reduced from
> an estimated 1.5 weeks to 3.5 days, and the press and personnel were then
> freed up for other jobs.
>
> Vanfu brought on board master printer, Katsumi Matsui, who has been printing
> on offset presses for over 50 years and has learned many tricks in his craft.
> He usually prints museum art reproductions using 12-unit presses and exotic
> materials like rice paper, foils and engraved embossing plates. He is a
> designated national treasure in Japan, and we were very fortunate to have his
> direction. He in turn was blown away by our success in color management and
> is now using it on all of his own presses.
>
> After experimenting with several high quality papers, we chose Oji Paper
> Golden Cask Dull. We printed on this satin paper, then the next day applied
> spot varnish to each photograph to bring out the colors and blacks.
> Matsui-san said it was better to let the four CMYK inks set overnight before
> applying the varnish. See page 207 of the pdf.
>
> After experimenting with several inks (including mismatched inks from
> different vendors), we chose the Toyo TK Hy-Unity soy inks. See page 122 of
> the pdf.
>
> We ran the press densities up and down to find the optimum sweet spot that
> gave the widest gamut without clogging up the shadows or sticking to the sheet
> above. We printed simple targets at a wide range of densities, then measured
> them and examined the measurements in Chromix ColorThink to monitor the
> changes in gamut in different parts of the color space.
>
> We tested different screening techniques, and ended up choosing Dainippon
> Screen's software RIP with Screen SPEKTA hybrid AM/FM screening technology.
> It gave smooth gradations in the midtones and kept more details in the
> highlights and shadows. By varying both dot size and dot placement, it gave
> good repeatability, detail and gradations.
>
> In our quest for wider gamut, Matsui-san added a drying agent to the inks to
> make them more tacky so we could lay down more ink. See page 125 of the pdf.
>
> Matsui-san also increased the offset powder in the output stage from a normal
> 2% to 8%. These fine granulated starch particles help to keep the ink on one
> sheet from sticking to the sheet above, especially as the sheets get stacked
> several inches tall. At 8% offset powder, the finished printed sheets felt a
> little gritty, so after drying overnight an aerated jogger was used to blow
> out the starch particles before the varnish.
>
> On page 141 and 159 of the pdf you can see the densitometer used for all
> measurements. It is the standard scanning densitometer built into the
> Heidelberg press console. I do not know whether it was statusE or statusT.
> Perhaps you can research how Heidelberg normally configures it for press
> consoles sold to Japan. Please let me know what you find. On page 143, 145,
> 177 you can see the actual density measurements including the bar graph
> showing density measurements across the width of the paper.
>
> Four-up ECI 2002 targets were printed and measured on a Gretag SpectroScan.
> The four targets were rotated and arranged on the press sheet so as to cancel
> out minor density variations across the width of the press. Four targets from
> one press sheet were measured and averaged with rejecting outliers. See pages
> 138, 138, 146-148.
>
> I don't remember whether the SpectroScan was outfitted with a UV filter. In
> my own measurements I always use one. I enclose a file of the averaged
> measurements [a copy of Bill's Lab measurement file may be downloaded at
> <http://tinyurl.com/4e5vdz> - Marco] which can be opened in Gretag
> MeasureTool, Chromix ColorThink, or any text editor. The measurements were
> made without varnishing the targets. I had previously done some tests at home
> that showed this to work better, perhaps because the spot varnish on the
> photos does not cover the white paper surrounding them.
>
> I used the same set of measurements to build profiles with seven different
> software and parameter settings, and used the profiles to print hard copy
> press proofs on an Epson 9600. See page 167 of the pdf. After examining the
> press proofs and comparing them to inkjet prints without proofing, I chose the
> ColorSavvy profile with all default settings as a clear winner over
> ProfileMaker4, MonacoColor, and several other profile making softwares.
>
> I made this choice in spite of the fact that the ColorSavvy profile had only
> eight-bit lookup tables and only used a 754 patch subset of the ECI 2002
> target measurements. ColorSavvy's nonlinear gamut mapping with a progressive
> tax on saturation clearly gave better results with these colorful rock images.
> The other profiles gave excessive desaturation and a loss of texture and
> detail in the saturated parts of the photographs. More recent versions of
> ProfileMaker and MonacoColor have improved gamut mapping.
>
> My book was delivered to Vanfu as a pdf file written from InDesign, with all
> the photographs from Lab tifs. The ColorSavvy press profile was installed in
> Vanfu's RIP and was used to convert the pdf's Lab colors directly into Vanfu
> CMYK. No hand tuning was used for any of the separations. Plates were burned
> directly from the RIP on a Screen Plate-Rite 8600 thermal CTP platesetter
> using Kodak Polychrome DiamondPlate LT-3 media. By not using a film
> intermediate we avoided any dot gain variability in the transfer. See page
> 155.
>
> The first sheet we printed with the new press profile contained small versions
> of all 72 colorful rock photos. All were nearly perfect, and Matsui-san was
> blown away. Many looked considerably better than the Epson 9600 inkjet prints
> because the press blacks were deeper. See page 162, 167.
>
> During each press run, the press operator pulled every 500th sheet without
> stopping the press, and used the scanning densitometer on the press console to
> monitor the color bars on the edge of the sheet. The press operator then
> adjusted the press to keep to the sweet spot densities. We found it important
> to track not only 100% ink densities, but also 50%, 25% and 75% densities.
> When those all read the same as the color bars on the profile target sheet,
> the press printed exactly the same and the profile worked perfectly.
>
> When re-training press operators out of their old trial and error habits, I at
> first withheld any proofs from them until they had brought the press to the
> agreed on sweet spot densities. I would then slap down the inkjet proof and
> they would be amazed every time. Slowly they learned to just print to density
> by the numbers and only use the proof as a sanity check rather than using it
> to adjust the press by eye. Their job was to monitor the color bars and
> adjust the press to keep it printing the same as it did for the profile
> target. When they did that, they got an excellent color match every time.
>
> I have spent several hours preparing this email for you. I hope it does you
> and others some good, and I wish you well in your printing projects. Please
> feel free to post this email and forward it to other printers who would
> benefit from it. I am very busy, and am not available as a color management
> consultant, but perhaps this email and the pdf on my downloads page will help
> others to benefit from my wonderful printing experience with Vanfu.
>
> Best wishes, Bill
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