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Exposure/washout units

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  • dpwall@hotmail.com
    I am interested in hearing some of the pros and cons of the various machines as they compare to one another. Can anyone offer opinions in this regard? Thanks,
    Message 1 of 14 , Sep 21, 2001
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      I am interested in hearing some of the pros and cons of the various
      machines as they compare to one another. Can anyone offer opinions in
      this regard?

      Thanks,

      David Wall
    • Frank Cabral
      Hello David, We use a Anderson Vreeland orbital washout unit. It is very simple and does not have many variables. It is basically exposing the properly dense
      Message 2 of 14 , Sep 21, 2001
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        Hello David,
        We use a Anderson Vreeland orbital washout unit. It is very simple and does
        not have many variables. It is basically exposing the properly dense
        negative, (4.0 at least, I like them digitally output of at least 1200 dpi)
        emulsion side down on the plate material for about 2.5 minutes, this is one
        of the areas where you can affect the plate. I find the MLD 145 plate
        material the best for type and where you need crisp edges I will use the
        softer plate material for printing solids. Once exposed the plate is
        attached to the magnetic orbital part of the unit and washed out with water
        for about 4 minutes. At one time I would wash it out for 2 minutes put the
        plate in the oven and dry it for 10 minutes and then wash it out for 2
        minutes then complete the drying for 20 minutes with a final exposure 4
        minutes to harden the entire plate. I have used this process with film that
        is not as dense or with very fine lines or small dots or where there is a
        lot of space between images. When I make a bad plate it is generally that
        the film was not dark enough, I exposed the wrong side of the film or the
        suction holding the kreen in place was not sufficient, all of this
        allowing to much light in to harden parts of plate that should be washed
        out. At one time a representative of AV suggested we put in vinegar in the
        washout water, at that time we had treated water, that worked fine until we
        put in a well and had the water filtered and softened which reacted with
        the vinegar and produced unstable plates, granular edges. I stopped using
        the vinegar and the problem vanished. It took a long time to figure that
        one out. I have only used this machine and have no comparison. I feel very
        confident in being able to produce excellent plates. Last summer I made
        about 230 8"x 10" plates of 16 pt text and had two bad plates, one I should
        have replaced the kreen sooner the other there was a speck between the
        negative and kreen which produced some broken letters. I will be interested
        in the experience of others with this and other machines.

        Frank
        cabral@...
        Nevada City

        dpwall@... wrote:

        >
        > I am interested in hearing some of the pros and cons of the various
        > machines as they compare to one another. Can anyone offer opinions in
        > this regard?
        >
        > Thanks,
        >
        > David Wall
        >
        >
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        [Non-text portions of this message have been removed]
      • Gerald Lange
        ... Dear Frank My A&V rep told me the same thing, and I always put vinegar in the wash (he said a cupful). He said it would keep mineral deposits from
        Message 3 of 14 , Sep 30, 2001
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          > Frank Cabral wrote....At one time a representative of AV suggested we put in
          > vinegar in the washout water, at that time we had treated water, that worked
          > fine until we put in a well and had the water filtered and softened which
          > reacted with the vinegar and produced unstable plates, granular edges. I
          > stopped using the vinegar and the problem vanished. It took a long time to
          > figure that one out....


          Dear Frank

          My A&V rep told me the same thing, and I always put vinegar in the
          wash (he said a cupful). He said it would keep mineral deposits from
          accumulating (it also apparently helps suspend the waste material—
          techanically termed inspissation!!!).

          When a BASF sales rep came in to try and sell me the new water-washout
          plates they are making for flexography he said the only requirements
          for conversion were extremely high temperatures and a soft water
          hookup. I didn't bother to didn't ask about vinegar.

          It just might well be that a certain acid/akaline balance is somewhat
          important.

          Gerald
        • Frank Cabral
          Hello Gerald, I think you are correct about that balance. Yet another variable. The A&V rep also suggested to have the water temperature at 110 F. for
          Message 4 of 14 , Oct 1, 2001
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            Hello Gerald,

            I think you are correct about that balance.
            Yet another variable. The A&V rep also suggested to have the water
            temperature at 110 F. for processing the MLD 145. I have found better
            results keeping the water about 85 degrees (as with the KM 152 plate
            material). With the higher temp. it was to easy to wash away fragile
            isolated dots or the edges of fine type.

            Frank
          • Gerald Lange
            Dear Frank Since we are using the same machine I have some questions I hope you will address. I also keep the temperature down a bit. 90 to 100 max for KM 95s
            Message 5 of 14 , Oct 1, 2001
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              Dear Frank

              Since we are using the same machine I have some questions I hope you
              will address. I also keep the temperature down a bit. 90 to 100 max
              for KM 95s (.038).

              But I would like to know your exposure times for KM 152 (.060). You
              wash these out for four minutes right? What are your exposure settings
              here for say reverses,/solids, then type, then fine lines/halftones?

              And a curious question, why MLD 145s for text? These aren't even on my
              spec sheet for letterpress!!!! Aren't the MLDs for molds, hot
              stamping, flexography, rubber stamps, etc.? How did you get to this
              choice?

              Gerald


              --- In PPLetterpress@y..., Frank Cabral <cabral@j...> wrote:
              >
              > Hello Gerald,
              >
              > I think you are correct about that balance.
              > Yet another variable. The A&V rep also suggested to have the water
              > temperature at 110 F. for processing the MLD 145. I have found better
              > results keeping the water about 85 degrees (as with the KM 152 plate
              > material). With the higher temp. it was to easy to wash away fragile
              > isolated dots or the edges of fine type.
              >
              > Frank
            • Frank Cabral
              Dear Gerald The exposure for the KM 152, depending on image, the more solid the shorter, is for about 2.5 minutes and wash out about 3 minutes. I have found
              Message 6 of 14 , Oct 2, 2001
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                Dear Gerald

                The exposure for the KM 152, depending on image, the more solid the
                shorter, is for about 2.5 minutes and wash out about 3 minutes. I have
                found that this material is easier to wash away. After about two and half
                minutes I will check with a loupe every 15 to 30 seconds until the bevel on
                the edge is correct and that the periods, dots over 'i' and end of lines
                are not undercut. The arrangement of positive and negative space on the
                negative will affect this.

                I will use the KM 152 for solids, when the general image is large
                (backgrounds, large block type etc.) While this material is capable of
                holding fine lines I find when printing that it is a softer, more generous
                and will spread more than the MLD. The 152 is great for printing on plastic
                and responds best to soft packing.

                MLD after the final exposure is quite hard, but brittle, and holds up to
                the letterpress look (deep impression) that is so popular today. I have
                found it holds fine lines and dots with a longer washout than the 152. The
                longer washout is important, it reveals the edges of the typeface, washes
                away the shoulder and makes the printing more accurate as to its design.
                Especially on the different surfaces and thickness of paper. Printing is
                primarily on 10x15 Heildelbergs' and 21x28 Heidelberg cylinder presses.

                I don't remember how I got to this choice but it has worked so well I
                haven't found a reason to look further. Most problems are operator error
                either in how I made the plates, my make ready or some mystery that is
                plainly obvious to everyone but me.

                I think the spec sheet I have for MLD recommends it for all the
                processes you mention but I thought it also included letterpress. I will be
                at the shop tomorrow if it is any different I will send you a note.

                What material do you use?

                With regards
                Frank


                Gerald Lange wrote:

                > Dear Frank
                >
                > Since we are using the same machine I have some questions I hope you
                > will address. I also keep the temperature down a bit. 90 to 100 max
                > for KM 95s (.038).
                >
                > But I would like to know your exposure times for KM 152 (.060). You
                > wash these out for four minutes right? What are your exposure settings
                > here for say reverses,/solids, then type, then fine lines/halftones?
                >
                > And a curious question, why MLD 145s for text? These aren't even on my
                > spec sheet for letterpress!!!! Aren't the MLDs for molds, hot
                > stamping, flexography, rubber stamps, etc.? How did you get to this
                > choice?
                >
                > Gerald
                >


                [Non-text portions of this message have been removed]
              • typetom@aol.com
                Hello Gerald & others, With such variations apparent in different plates, it would help my perspective if you might label the brand or source of the various
                Message 7 of 14 , Oct 2, 2001
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                  Hello Gerald & others,
                  With such variations apparent in different plates, it would help my
                  perspective if you might label the brand or source of the various plate
                  materials you are describing. I am using Gene Becker's Miraclon MS152 plates
                  in a home-made, handwashed system, getting good results (within a long
                  process of adjustments and fine tuning and experimenting). But I am
                  continually amazed at how divergent everyone's answers are: I hardly ever
                  hear the same instructions, exposure times, washout times, proceedures, etc,
                  despite how certain and enthusiastic we all are about our results. I have
                  projected the same certainty at times, only to realize later that I had
                  misinterpreted some factor or another. Correctly diagnosing problems in this
                  technology remains a humbling mystery, despite my being able to use it
                  successfully for numerous commercial and artistic projects.

                  Another request: I wonder if someone might describe the machine washout. Does
                  the machine fill up with water and soak before brushing? Or maybe pause
                  brushing and soak occasionally? For how long? Or is it all continuous action?
                  And is there any method used for observing/evaluating the progress, or is it
                  just a timed setting? In hand-washout, I am continually checking, and choose
                  to halt early or continue washing down to clean metal backing according to
                  the specific details of the plate. I have wondered how this could be possible
                  in the machine.

                  Any rate, thanks for carrying on so -- I'm listening with interest.
                  Best wishes, Tom

                  Tom Parson
                  Now It's Up To You Publications
                  157 S. Logan, Denver CO 80209
                  (303) 777-8951
                  http://members.aol.com/typetom
                • Gerald Lange
                  Dear Tom Don t really know how to address the first issue. Economics is a big factor here. If you are not doing industry standard (and to do so requires
                  Message 8 of 14 , Oct 3, 2001
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                    Dear Tom

                    Don't really know how to address the first issue. Economics is a big
                    factor here. If you are not doing "industry standard" (and to do so
                    requires owning variously expensive equipment; processing machine,
                    bases, etc., all of which have their own uniquely varied
                    requirements) you are doing "alt," and in alternative processing the
                    techniques and materials employed are so varied, subjective, and
                    discontinuous one to another that to speculate on their relative
                    merits or demerits is foolhardy.

                    I'd like to think this must be somewhat akin to the problems that
                    Monotype must have faced. Now that they've potentially put a possible
                    foundry into every printshop, how do they regulate it? Their answer
                    seems to have been, to not regulate. Give the caster the ability to
                    alter character positioning, metallurgy, type height, etc. Hmm, maybe
                    not the best analogy after all.

                    Maybe I can do better on machine washout. Well, the machine should
                    fill up with water to some point just above the brushes. My rep says a
                    quarter of an inch, and I believe every word he says. The machine has
                    a cyclical pattern that seems to brush, halter, and brush again. It
                    could be reversing the pattern, I do not know. The machine is closed
                    during the process. The halting is only for a second or two. The
                    machines are timed-set. It is initially a matter of trial and error to
                    find the correct timing though there is certainly enough info out
                    there to get you on the right track quite quickly. This of course
                    various with different configurations of plates. Nothing but variables
                    in photopolymer I'm afraid. Trick, I quess, is to find your own here.

                    Regarding the checking. I never do this. I don't know what I could
                    tell by what I was seeing anyway. This may probably be a good idea,
                    whether you are doing this by machine (as Frank does) or by hand (as
                    you are), but I assume you need the eye for it. If I've had problems
                    (other than the purely mechanical) they have generally been in exposure
                    because I have knowingly taken shortcuts, specifically, ganging plates
                    or running different weights of text or formats together or, the worst,
                    saying yes to the client who prefers to furnish their own plates. I do
                    a certain amount of hand washing out for a specific kind of plate and
                    I try to mimic what I believe are the actions of the machine. I have a
                    little contraption built for this that I use in the machine, against the
                    brushes; I think I may have mentioned this in a very early post. Personally,
                    hand-washing scares the crap out of me. I do a lot of bookwork mainly so
                    consistency is quite crucial to me. I'm under the opinion that seconds
                    count here and I don't trust variables in regard to processing.

                    Doubt if this answers or resolves anything. But it was a good question
                    and, since no one else jumped at it, I thought it worth a shot.

                    All best

                    Gerald

                    > Hello Gerald & others,
                    > With such variations apparent in different plates, it would help my
                    > perspective if you might label the brand or source of the various plate
                    > materials you are describing. I am using Gene Becker's Miraclon MS152 pla=tes
                    > in a home-made, handwashed system, getting good results (within a long
                    > process of adjustments and fine tuning and experimenting). But I am
                    > continually amazed at how divergent everyone's answers are: I hardly ever=
                    > hear the same instructions, exposure times, washout times, proceedures, e=tc,
                    > despite how certain and enthusiastic we all are about our results. I have=
                    > projected the same certainty at times, only to realize later that I had
                    > misinterpreted some factor or another. Correctly diagnosing problems in t=his
                    > technology remains a humbling mystery, despite my being able to use it
                    > successfully for numerous commercial and artistic projects.
                    >
                    > Another request: I wonder if someone might describe the machine washout. =Does
                    > the machine fill up with water and soak before brushing? Or maybe pause
                    > brushing and soak occasionally? For how long? Or is it all continuous act=ion?
                    > And is there any method used for observing/evaluating the progress, or is= it
                    > just a timed setting? In hand-washout, I am continually checking, and cho=ose
                    > to halt early or continue washing down to clean metal backing according t=o
                    > the specific details of the plate. I have wondered how this could be poss=ible
                    > in the machine.
                    >
                    > Any rate, thanks for carrying on so -- I'm listening with interest.
                    > Best wishes, Tom
                    >
                    > Tom Parson
                    > Now It's Up To You Publications
                    > 157 S. Logan, Denver CO 80209
                    > (303) 777-8951
                    > http://members.aol.com/typetom
                  • Harold Kyle
                    Tom, I had thought, much like you do, that hand-washing would be accurate than machine washing--until I recently switched over to a machine washout. I
                    Message 9 of 14 , Oct 4, 2001
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                      Tom,

                      I had thought, much like you do, that hand-washing would be accurate
                      than machine washing--until I recently switched over to a machine
                      washout. I purchased the machine for better exposure and for
                      convenience, but didn't anticipate better washout.

                      In fact, the machine washout produces noticeably better plates. The
                      main advantage to the machine is its evenness of pressure. You don't
                      need to check the plate periodically for unwashed areas because the
                      whole plate washes out at the same rate. Corners took notoriously
                      long to wash out by hand; now, I don't have to worry about overdoing
                      the washout in the center. This isn't such a problem on type, but a
                      10% or 5% screen in the middle of your plate will suffer from
                      excessive washout. Because its pressure is constant, it doesn't tend
                      to wash away isolated dots as easily.

                      Since the machine brushes are larger, they also get the plate out of
                      the water sooner. Some plates, especially the large (say, 11x17)
                      ones, had to remain underwater for 10+ minutes to wash out with a 4x8
                      brush. Leaving them underwater so long can cause delamination of the
                      plate. Oh, and the machine brushes don't have hard plastic corners
                      that can scratch the surface of your plate.

                      Handwashing works. Telling the difference between a machine washed
                      plate and a hand washed plate (by someone who has excellent
                      technique) would be impossible on most small plates. But for large
                      plates or ones with isolated dots, light screens, or very small text,
                      machine washing works much better.

                      Harold Kyle
                      www.boxcarpress.com
                    • typetom@aol.com
                      Thanks Gerald, Your description of the washout machine action is about as I imagined, having only seen one not in operation. My washout time is presently quite
                      Message 10 of 14 , Oct 4, 2001
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                        Thanks Gerald,
                        Your description of the washout machine action is about as I imagined, having
                        only seen one not in operation. My washout time is presently quite a bit
                        longer than others have mentioned, perhaps because I use a very soft brush
                        and only very gently agitate. Obviously still some room for experimentation
                        here, but my results now are quite consistent and it seems possible to
                        control it by hand washing.

                        My first question was probably simpler than your answer: just that the plate
                        references (such as MK or MLD) don't tell me much unless I am using the same
                        source for plates, I think. Would the MK152 be the same as the MS152 I get
                        from Gene Becker? Maybe I just need to go back to the various notes Gene gave
                        me to see if the answer is there. Similarly, I have had some difficulty
                        making comparison with materials supplied by NA Graphics, because the names
                        differ. So I thought it might help if I say Gene Becker's Miraclon MS152
                        rather than 152 or MS152....

                        Regarding toxicity, it sounds like it's a question of skin sensitivity rather
                        than poison or carcinogin. I have hand-washed maybe 40 sheets (A3 size,
                        297x420 mm = 11x15? cut to innumerable smaller plates) over six years or so.
                        No gloves. No noticable skin reaction, no other problems at all (except an
                        occasional cut from the sharp edge of the metal backing, of course). I do
                        keep the water running slightly (to keep the temperature constant) so maybe
                        the concentration is low. Or maybe I'm just not sensitive. So far, it seems
                        to me remarkably benign. The very slight odor from unexposed material also
                        seems inconsequential to me. UV light, of course, is bad for the eyes (and
                        skin as well, I think).

                        Best regards, Tom

                        Tom Parson
                        Now It's Up To You Publications
                        157 S. Logan, Denver CO 80209
                        (303) 777-8951
                        http://members.aol.com/typetom
                      • Frank Cabral
                        Hello Tom, The orbital washout unit has been the only way I have been able to produce consistently good plates efficiently. The time factor is very important.
                        Message 11 of 14 , Oct 4, 2001
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                          Hello Tom,
                          The orbital washout unit has been the only way I have been able to produce
                          consistently good plates efficiently. The time factor is very important.
                          About twenty years ago, when the photo polymer was just entering the
                          market, I was told by salesmen that the plate could be exposed in the sun
                          and washed out in a sink with any brush. I spent what seemed and endless
                          amount of time discovering only that there are many variables. I built
                          things, converted things, nothing I did seemed to have the same results
                          twice, or that the plates were just not good enough. I like process, but I
                          was always off task trying to find a solution.
                          While not quite a glorious epiphany, the machine allowed me to make
                          accurate plates, in a short time with not so much guess work. I only had to
                          pay attention to the orientation and density of the negative, the suction
                          of the vacuum table, cleanliness of the kreene, monitor the wash out, water
                          temperature, drying and final exposure to harden the material. The process
                          is simple and consistent (generally).
                          I like to examine the plate during washout to check that as much
                          material has washed away as possible but not so much as to weaken its
                          structural integrity , (small bits of the design, or letters that break off
                          during printing that you don't notice until you are finished).
                          Gerald has a good explanation of the washout process.
                          I think Monotype had much more exacting details built into their
                          production, and while success at times seems atmospheric the documentation
                          they provided would allow you some success. There are just so many pieces
                          to pull together and each one requires complete attention to detail.

                          If you contact me off list I can send you some plate processing
                          instructions for Miraclon/Rigilon, this is the MLD made by Toyoba. They
                          also recommend it for crash printing, hot stamping and for pantograph
                          masters. I have only used it for letterpress printing.

                          Regards
                          Frank
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