Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,564   Posts: 1,573,402   Online: 890
      
Page 13 of 17 FirstFirst ... 37891011121314151617 LastLast
Results 121 to 130 of 162
  1. #121
    holmburgers's Avatar
    Join Date
    Aug 2009
    Location
    Rochester NY (native KS)
    Shooter
    Multi Format
    Posts
    4,423
    Images
    2

    Henry Wilhelm's Take on UltraStable

    Charles was kind enough to share this document with me, and I hope he doesn't mind if I share it with you.

    It is the author's opinion that UltraStable Permanent Color prints likely will last even longer than carefully-processed, fiber-base black-and-white photographs!
    Attached Files

  2. #122

    Join Date
    Jul 2011
    Shooter
    8x10 Format
    Posts
    2,777
    For me the holy grail of carbon printing would be a set of highly transparent process colors rather than the relatively opaque traditional choices. Truly premium watercolor hues would be far too expensive to make in quantity, and commercial varieties inevitably tend to incorporate preservatives
    which cause serious problems, and don't offer an equally permanent yellow anyway. There is a way
    to enclose cadmium in clear titanium, but anything to do with cadmium is now outlawed in the EU where they know how to do this. I've got a good lead on serious alternative technology, but am stuck with finding a suitable process cyan. So far, can only get there by mixing pthalo blue and green. Would like a cleaner magenta too. Custom mfg of process colors per se would be very expensive, but technologically very feasible. The problem is, that in industrial usage, opaqueness is
    an asset. Don't want to divulge too much at this point, since I simply don't have time to test this
    or that. Maybe after I retire I can contribute some tidbit to the carbon theme, since I love the look
    of these prints and understand pigments better than most.

  3. #123
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,405
    Images
    65
    Considering the difference of opinion over the Wilhelm tests of Endura vs CA papers, I would say the tests depend on the test conditions which should also include heat, humidity and pollutants. Henry is not covering everything in that article IMHO.

    Transparent carbon "pigments" were sold years ago on tissues for printing color carbons. I think Defender was one of the suppliers.

    PE

  4. #124

    Join Date
    Jul 2011
    Shooter
    8x10 Format
    Posts
    2,777
    Since carbon tissue pigments don't have to be ultra-fine like inkjet color, this allows more flexibility in choice,
    including better permanence, though in certain pigment categories, very small particle size can equate to better
    transparency in the overall sandwich. Old-school Fresson prints used a choice of process colors which by today's
    standards would be considered poor from both a hue and permanence perspective, but I wouldn't be surprised if they were more permanent than most current inkjet offerings, simply because you've only got CMYK to deal with,
    and not a complicated blend of many different programmable jet nozzels. Then folks started looking into auto pigments etc. Certain watercolors were used also, and I certainly preferred their look to the more mechanized
    schools are pigment printing, but can understand their relative inconvenience due to batch variability. I've had
    some pretty extended conversations with Aardenburg and do think he intelligently addresses some of the shortcoming in Wilhelm's approach. But having had many years of experience dealing with industrial pigments and how accelerated aging tests work, I take all of them with a degree of caution. For instance, I would never ever claim any print I sell will last so many decades because some lab extrapolated it. That's marketing bull as far as I'm concerned. But given an intelligent choice of pigments, a modern carbon print should resist fading longer than any of the common alternatives, including inkjet. The integrity of the sandwich and substrate is a
    whole different issue, however, and has its own weak spots in prediction.

  5. #125
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,405
    Images
    65
    Hmmm, thinking this over, how about breaking open a set of C/M/Y pigment inkjet cartridges and mixing them into glop! Then you can test them out in Carbon printing.

    PE

  6. #126

    Join Date
    Feb 2011
    Shooter
    35mm
    Posts
    131
    Quote Originally Posted by Photo Engineer View Post
    Hmmm, thinking this over, how about breaking open a set of C/M/Y pigment inkjet cartridges and mixing them into glop! Then you can test them out in Carbon printing.

    PE
    I have no particular interest in this topic having just stumbled upon it but why break open three expensive cartridges when you can buy 3rd party refill inks - there are some pigment inks available for Epson Photo printers and while perhaps not as good as the OEM inks they may serve for experimention. OzJohn

  7. #127
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,405
    Images
    65
    Oz;

    My problem is that I am an ANALOG guy and didn't know anything about what you posted.

    Thank you.

    PE

  8. #128
    Hexavalent's Avatar
    Join Date
    Nov 2009
    Location
    Ottawa, Ontario, Canada
    Shooter
    Multi Format
    Posts
    549
    Blog Entries
    3
    Quote Originally Posted by Photo Engineer View Post
    Hmmm, thinking this over, how about breaking open a set of C/M/Y pigment inkjet cartridges and mixing them into glop! Then you can test them out in Carbon printing.

    PE
    Tried that.. still trying to get the stains out. "Pigment" inks act more like dyes than typical pigments.
    - Ian

  9. #129

    Join Date
    Feb 2011
    Shooter
    35mm
    Posts
    131
    Quote Originally Posted by Photo Engineer View Post
    Oz;

    My problem is that I am an ANALOG guy and didn't know anything about what you posted.

    Thank you.

    PE
    It's feels good to tempt fate occasionally! OzJohn

  10. #130

    Join Date
    Jul 2011
    Shooter
    8x10 Format
    Posts
    2,777
    Ron - all the pigments used in any of the commercial carbon or carbro processes would be classified as opaque. They allow light to pass around
    them because the dispersion is relatively thin. But the ability to hypothetically make true transparent process pigment is relatively new
    technology. There are a couple of ways to do it, but all the carbon printers in the world would not be enough incentive for a manufacturer to make money on a custom batch. Somone would have to finance it just for the love of the medium. Inkjet pigments are really complex blends of dyes,
    pigments, and lakes. But permanence is not their first priority. You can learn a lot about them from the underlying patents. The bigger issue is
    dispersant technology, and here there are some serious trade secret involved. Given all the added ingredients in inkjet colors, it probable they'd
    do poorly in a carbon or carbro application. What I'd really like to see is
    the kind of glow one gets with a dye transfer print with the permanence
    and scale of a carbon. The clues are out there, but probably not in photographic literature per se.



 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin