Color balance For Gum Prints

Discussion in 'Alternative Processes' started by Bruce, Oct 26, 2010.

  1. Bruce

    Bruce Subscriber

    Messages:
    74
    Joined:
    Jul 8, 2007
    Location:
    Centerville
    Shooter:
    35mm
    Gum Printers

    How do you achieve color balance for gum prints?

    I am trying to do Tri-Color gum and can't seem to get a decent print. Most are to muddy in color after my 3 coatings.

    I assume I just have to work with the individual pigment strengts to get the right set of pigment/gum strengths and also work with the exposure time to get a balance I like.

    What are your thoughts?


    Thanks!

    Bruce
     
  2. sly

    sly Subscriber

    Messages:
    1,507
    Joined:
    Nov 12, 2006
    Location:
    Nanaimo
    Shooter:
    Multi Format
    How are you making your separation negs?
     
  3. tiberiustibz

    tiberiustibz Member

    Messages:
    1,749
    Joined:
    Oct 22, 2007
    Location:
    Tufts Univer
    Shooter:
    35mm
    Wasn't there an article on this on unblinkingeye or something? I think that person was using a hybrid workflow, and they had gotten the optimal curves to use with the process characteristics to prevent crossover etc.

    As I recall the critical factor was that the bottom dye could be opaque, but the top two had to be translucent. Not sure of the dye nomenclature but if the top dyes are opaque you won't see the bottom ones.
     
  4. Jim Noel

    Jim Noel Member

    Messages:
    2,165
    Joined:
    Mar 6, 2005
    Shooter:
    Large Format
    It takes a lot of research and trial and error to learn to do well with this process. The best information available is in Christina Anderson's book "Alternative Processes Condensed". She has done all the research and is a very thorough worker and teacher.
    As far as the negative separations are concerned again you have to work on the curves until they work for you. I have one former student who produces 3 color gums that look like paintings. It took her about 6 weeks of experimentation to get the curves the way she wanted them.
    Anyone who is successful with the process goes through the testing. You can not depend on someone else providing the answers for you.
     
  5. Bruce

    Bruce Subscriber

    Messages:
    74
    Joined:
    Jul 8, 2007
    Location:
    Centerville
    Shooter:
    35mm
    I am using the same negatives that we used during the workshop so I know that is not the problem.


    Bruce
     
  6. sly

    sly Subscriber

    Messages:
    1,507
    Joined:
    Nov 12, 2006
    Location:
    Nanaimo
    Shooter:
    Multi Format
    I'll second the recommendation for Christina Anderson's book. There are so many variables besides the negatives - the paper, the sizing, the pigments, the pigment/gum ratio. It's a frustrating, challenging, fascinating process. If you did a workshop, and got good results there, you'll have to figure out which variable(s) is(are) different.
     
  7. Bruce

    Bruce Subscriber

    Messages:
    74
    Joined:
    Jul 8, 2007
    Location:
    Centerville
    Shooter:
    35mm
    Jim and Sly

    Yes, I have Chris's book, and took a wonderful workshop from her. I am now trying to get similar results at home. As you both said, there are many variable so I'll just keep printing until I get better results.

    Thanks for the help.

    Bruce
     
  8. holmburgers

    holmburgers Member

    Messages:
    4,423
    Joined:
    Aug 13, 2009
    Location:
    Rochester NY
    Shooter:
    Multi Format
    Dear Abby,

    What pigments do you folks use, and where do you get them?

    Ever tried dyes instead?

    Curious in Lawrence

    :wink:
     
  9. Loris Medici

    Loris Medici Member

    Messages:
    653
    Joined:
    Sep 13, 2005
    Location:
    Istanbul, Tu
    Shooter:
    Multi Format
    holmburgers, I think water soluble colorants aren't suitable for gum dichromate; just picture the leeching of dyes in the development stage; the principle of gum dichromate is trapping "pigment" "particles" in the "poriferous structure" of hardened gum - induced by the action of light on dichromate...
     
  10. holmburgers

    holmburgers Member

    Messages:
    4,423
    Joined:
    Aug 13, 2009
    Location:
    Rochester NY
    Shooter:
    Multi Format
    I wonder if there's a mordant that would make this feasible?

    Anyways, I'm more interested in pigments as it is; longer life, no fade.

    Thanks!