Mounting paper to a substrate for good registration of gum prints

Discussion in 'Alternative Processes' started by BenjaminAustin, Oct 22, 2011.

  1. BenjaminAustin

    BenjaminAustin Member

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    Hi All,

    In the same vein of my emulsion coating stories, I thought I'd talk a bit about my mounting experiences to help beginners and invite some constructive input from the old hands.

    I have always had trouble with registration on my gum prints as the paper - even when pre-shrunk - will change dimension every wet/dry cycle. I have tried a number of different methods to mount the paper to a variety of surfaces.

    Aluminium Sheets
    Some people swear by this stuff. So I schmoozed one of the big commercial offset presses here in sydney to hand over some of their waste plates and cut them down to mount my paper. I tried hot mount material - but only have a hand iron. That wasn't terribly successful, and was not practical for larger sheets - over 1 meter.
    I tried diluted PVA glue - this works to a degree - however I found the paper released prematurely after one or two soaks. In addition, the aluminium sheet is very thin and bows to a degree that makes coating the emulsion difficult.
    I have abandoned thin aluminium sheeting as an option for larger works.

    Perspex
    Same as the aluminium sheet. Gluing releases prematurely and the sheet bows excessively - even using 4ml perspex.

    Alu-Panel
    This stuff is great. Its very stiff so it doesn't bow enough to disrupt coating. Its got a number of names - signboard, dibond etc... Its two thin aluminium sheets sandwiching some kind of plastic. One side has a gloss finish and the other is slightly matted. I had some big 1200mm x 2400mm boards cut down to my paper sizes and use those.

    Mounting Methods
    As I mentioned, I tried PVA. It releases prematurely. I tried spray adhesive - thats a dead end, and I tried dry mounting tissue - which I'm sure would be fantastic - but a mounting press is beyond my budget, Particularly on the scale I'm working at.
    I have found a certain amount of success by borrowing some old watercolourist wisdom. Watercolourists mount their paper to stop the paper buckling when painting washes. They soak the paper, then use gum tape - brown paper tape with a coating of gum arabic on one side - to stick it down to a stiff board when wet.
    As the paper dries, it pulls itself tight as a drum. Great!
    When I first tried this - I thought all my problems were solved. Sadly, the paper is very strong - stronger proportionally with size. So the paper dried, pulled itself tight and then tore the gum tape. Once the tape is torn, the paper shrinks where it has released and any hope of registration is dashed.
    Take two. I thought some kind of mild adhesive might reduce the tension on the gum tape - so before laying the wet paper on the board, I pegged it up to let the excess water run off then sprayed some diluted gum arabic onto the back. I then taped it down with the gum tape. This was better but still released on occasion. The release was sometimes from the tape tearing, and sometimes from the gum letting go of the board.
    Take three (slightly exasperated by this stage). I did the same thing as before, but ran a bead of EVA glue around the outside rim of the paper to relieve the pressure on the tape. Voila!
    This seems to be doing the trick. The paper buckles a little while its wet, and floats around in the middle, but when dry, it pulls itself back into the same position layer after layer - and rego is great.

    I'm not entirely satisfied with how its working as it feels like its going to come off the board at any minute which is very stressful.
    I read Halvor Bjoerngaard's chiba study which mentions a method he has used to mount paper - I might try that soon.
    He coats the back of the paper with gelatin before gluing the paper to glass. The paper stays mounted until it is soaked in 40C+ water which melts the gelatin, and releases the paper.

    So at the moment, my problems are less with registration and more with the problem of unhardened pigment pooling on my wet prints and spreading into what are meant to be clean borders…

    Thanks for reading :smile:

    Any input appreciated. Hope this helps someone out there!

    B
     
  2. senojev

    senojev Member

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    Hi:

    I am just beginning gum printing and had all kinds of registration issues due to paper shrinkage. After some research, I found that preshrinking is a key step as is choice of paper. I switched to some 300lb Fabriano Artistico hot press that I shrank in 135 deg. F water for an hour, letting the water cool. After drying, I shrunk the paper again with minimal shrinkage of a full sheet. It dried perfectly flat. After the first printing, developing, drying, the paper was very flat and the neg registered perfectly with two registration pins. After five coats, I am still getting perfect alignment. With my approach, I do not see a need to use a substrate.

    I found a website, search for "Vedos" and in the archives under Gum, there are links to four youtube videos on substrate mounting that may help if you want to continue your approach.
     
  3. VesaL

    VesaL Member

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    I Have been Gum printing for couple of years time to time. What i have learned when making Gum prints, try the Fabriano artisico HP (hot pressed) type paper. Buy large sheets, cut them in desired size and soak the in HOT, almost boiling water for couple of minutes. Then hang to dry and coat them with hot gelatin and some hardener. This will give you quality paper with minimum shrinkage. It´s a tedious job, but, when you do it once and process lots of paper at that time, you have stock that will last for a while :0)

    If you want to see how artists can push the boundaries of Gum Printing, go to Flickr and search by the name of Hans De Bruijn. He has been my mentor.
     
  4. jon.oman

    jon.oman Member

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    Thanks for the link. He has some nice prints!