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  1. #121
    Dave Krueger's Avatar
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    I have been playing around with Dan's corrugated board stack drying scheme. It just so happens that it is easy to get sheets of 18"x24" corrugated board where I work, so I'm using those for 16x20s. That puts the long side of the print within a half inch of the edge of the board, but the interfacing overhangs by an inch or two more. I only tried it with one print, but it dried within about a day and a half or so. Not bad. Quite flat with a slight linear curl up at the ends. There is a very small waviness but it's on the short edge of the print which actually gets better coverage by the board. I placed a piece of 3/4 inch ply wood on top as a weight. I did not use any forced air.

    Since it seemed to work fairly well, I got a bunch more of the cardboard and will continue to use it. The interfacing is polyester and it's fairly thick (relative to some tissue-thin stuff I saw) and it didn't stick to the print or leave any kind of lint or marks in the emulsion. And it's pretty cheap. I have a mounting press, so I will flatten it in that to see if the slight waviness goes away completely after doing so, but for now it was flat enough to stick in a storage box with other prints (previously flattened with a press).

    Up to now, I've just laid prints out to dry on a paper covered table and they invariably curled which I would remedy by pressing them in a dry mount press. I don't mind using the press, but like others have said, the press will sometimes not be able to completely eliminate the warping along the edges that is due to nonuniform shrinkage during the drying process. This exercise with Dan's technique is basically to see I can improve things enough to get rid of that occasional residual warping.

    BTW, I use Ilford MGIV FB for these 16x20s. I don't think I've seen this residual warping on FB 8x10s.

  2. #122

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    Wondering

    Quote Originally Posted by Dave Krueger View Post
    This exercise with Dan's technique is basically to see
    I can improve things enough to get rid of that
    occasional residual warping.

    BTW, I use Ilford MGIV FB for these 16x20s.
    I don't think I've seen this residual warping
    on FB 8x10s.
    Wondering which way the flutes, corrugated channels,
    run, length wise or width wise? Also when doing 8x10s
    how many each layer? Dan

  3. #123
    Dave Krueger's Avatar
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    Dan,

    The flutes run width wise. I have not yet used the corrugated stack for 8x10s. Most of my 8x10s are on RC unless I'm experimenting with new paper types. I think I would be inclined to only do two 8x10s per layer since I don't have a lot of over-hang with the cardboard.

    This weekend I watched a documentary about Henri Cartier-Bresson and noticed, as he was thumbing through a bunch of prints (11x14, I think), they looked wavy along the edges.

  4. #124
    CBG
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    I just tried the taping to glass flattening method earlier in this thread. It works wonderfully.

  5. #125
    ruilourosa's Avatar
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    hello


    I think that music group called Bush inspired themselves to do a music in the solution of this problem


    GLYCERINE
    vive la resistance!

  6. #126
    ruilourosa's Avatar
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    make up a solution, try 5%, it will soften paper fibers and allow for a straighter drying, if you

    if you are ashamed of buying glycerine anywhere, try with KY jelly

    :-)
    vive la resistance!

  7. #127

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    commercial fb papers

    i work with ilford fb most of the time. primarily mgiv. ive seen a million posts on this. firstly, the bit about trimming the edges is true. the small waves along the length of the page seem to occur because of tension at the edge of the page. i dont know how they make their final products so i can assume a dozen reasons why this works but it just does. You only need trim less than 1/8 of an inch for it to be effective. you do so after you have processed the paper and have dried it to the point it no longer has a wet surface. but the paper is still saturated. i just lay it on a large cutting board (image up), use a straight edge and a very very sharp knife. There is technique to trimming wet photos. for example very light sawing at the start of the cut to ensure you are thru the paper before continuing or you will wrinkle the corner of your print, etc, etc, etc. I have never tried trimming an unexposed sheet. I hate trimming paper under a safe light.

    second, you can iron prints. what ever method for iron or heat drying you use, dont have anything in contact with the print that can transfer any residues or has any texture you dont want. the paper will pick up anything you touch to it, and will take on textures of fabrics and such you use to isolate the print from the iron. but ironing is a process to use if you are in a hurry, as is drier drums, heated blocks, etc. prints will stay flat because when they cooled and/or dried they were in a straight position. if you use anything with heat you should cool them with time and pressure method.

    Time is the best thing for fb print paper. air dry them until they are starting to curl and put them under flat weight. isolate them as mentioned. do not use things that absorb moisture. do not start this process if the print has not started to curl or you have rewetted portions of the paper. paper curls because it doesn't dry uniformly. the emulsion dries at one speed, the paper does another, and portions of the paper dry differently than other portions, also any hardeners such as hardening fixers can exaggerate the problem.

    i dont print more than a few 16x20's at a time. so i usually iron them and then put them under long term pressure. i live in florida. take a perfectly flat fb print and put it in the car and you get to start over again. So humidity is a factor. not just wet. remember that when you choose your isolation materials. if they hold moisture, they are maintaning a humidity level in your print. take it out in the ac and presto rollo.

  8. #128

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    some common sense about fibre prints:

    The paper side dries a lot slower than the emulsion side in air. The emulsion side dries a lot faster than the paper side. So when a print dries the emulsion shrinks and curls the paper. The paper side then dries but with all the fibres shifted so that it has a permanent curl.
    Then what happens is you stick it in a press. But because all the paper fibres are still dry and springy, all you do is put a temporary flatness in it which will eventually move back to its curled state as that is where the fibres dried.

    So the solution is, as bob carnie has already told you, to damp the print paper before putting it in the press. That way the fibres can move instead of just being sprung into a new position.

    And from all of that you should also be able glean that drying fibre prints very slowly will cause less curl and drying them face down on screens will limit airflow over the emulsion side so that the paper side dries relatively quicker causing less curl. But best of all, drying them very slowly in blotters with a weight on them will dry them perfectly flat with no tension in the paper fibres at all. That way they will stay flat even if not dry mounted.

    common sense really if you actually think about it.

    If you are the impatient type then you are stuffed.

  9. #129
    Mainecoonmaniac's Avatar
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    My observation

    I noticed that my FB prints are flatter the slower it dries. On humid days when my prints take a whole day to dry, they're kinda flat. But on those hot dry summer days when they dry in just a few hours, they are curly as a pigs tail. Don't know why.

  10. #130

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    Apologies if this is mentioned elsewhere in the thread--it's huge (I've been reading through it for a couple days and I'm not even halfway through).

    When I squeegee prints prior to hang-drying, they curl up like crazy. When I don't squeegee, they don't exactly dry flat, but pretty close. I'm thinking that my squeegee technique is lacking--perhaps I'm forcing water out of the center of the print, leaving more around the outside edge (or vice versa); thus uneven drying might result in curling. Also, when hang-drying, the bottom drys more slowly, thus stays slightly heavier throughout the drying.

    This is just theory, but based on observation. Thoughts, anyone?



 

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