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Re: [PPLetterpress] Photopolymer with 'moving' parts

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  • Gerald Lange
    Lola Your exposure time seems about right to me. But you really do need to test the exposure time with a 21 steps grey scale. With a hardness rating of 67 you
    Message 1 of 12 , Dec 3, 2012
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      Lola

      Your exposure time seems about right to me. But you really do need to
      test the exposure time with a 21 steps grey scale. With a hardness
      rating of 67 you should get a reading of 14-15 as solid—that means the
      14-15 boxes are not washed out or corroded (13 or below should be washed
      out). Exposure times can vary dependent upon the condition of your
      bulbs/ballasts. Fine lines or dots might need a slightly longer exposure
      time.

      Basically, you are not giving enough time to build a decent structural
      relief if your exposure/washout are out of sync and imaging is drifting.
      You do not have to back-exposure this plate, the manufacturer has
      already done that.

      You washout can vary quite a bit dependent upon bath temp, machine,
      brushes, etc. Mainly you want a clean floor with no undercutting of the
      surface imaging.

      Post exposure should be the same or longer than the main exposure. I
      usually do about 1.5x.

      It is difficult to "read" the validity of a plate immediately after
      washout because clinging moisture can cause optical distortion. Your
      drying temp seems high. Specs sheet recommends 60-70 C. I'm not sure if
      that is the problem but lower the temp and see if that helps.

      Gerald
      http://BielerPress.blogspot.com



      On 12/3/12 1:58 PM, tinglado_letterpress wrote:
      > Dear list members,
      >
      > I am using KF95 PP, processing the plate as follows: exposure: 200 s, wash out: 240 s / 21 ºC, dry out: 10 min at 80 ºC and post exposure 300 s.
      >
      > The main problem is that some letters (body size 6 pt) are pushed out of its possition in the PP. Please, check this picture to see what I mean (http://flic.kr/p/dyigw8). I checked it after wash out and they seem to be at the correct position. Do you think that it could be something related to the dry out process? Do you think that a bit of back exposure could fix the exposed photopolymer to the plastic base?
      >
      > The problem only happens with the '1' and the 'l' characters.
      >
      > I am in trouble, because it happens every time I try to process this work.
      >
      > Please, help!!!! :-)
      >
      > Thank you in advance and regards,
      >
    • Mª Dolores Jiménez Mondragón
      Thank you Gerald for you advices. I will try to improve those parts of the process and I will be back with the results. Regards, Lola 2012/12/3 Gerald Lange
      Message 2 of 12 , Dec 3, 2012
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        Thank you Gerald for you advices. I will try to improve those parts of the process and I will be back with the results.

        Regards,

        Lola


        2012/12/3 Gerald Lange <Bieler@...>
        Lola

        Your exposure time seems about right to me. But you really do need to
        test the exposure time with a 21 steps grey scale. With a hardness
        rating of 67 you should get a reading of 14-15 as solid—that means the
        14-15 boxes are not washed out or corroded (13 or below should be washed
        out). Exposure times can vary dependent upon the condition of your
        bulbs/ballasts. Fine lines or dots might need a slightly longer exposure
        time.

        Basically, you are not giving enough time to build a decent structural
        relief if your exposure/washout are out of sync and imaging is drifting.
        You do not have to back-exposure this plate, the manufacturer has
        already done that.

        You washout can vary quite a bit dependent upon bath temp, machine,
        brushes, etc. Mainly you want a clean floor with no undercutting of the
        surface imaging.

        Post exposure should be the same or longer than the main exposure. I
        usually do about 1.5x.

        It is difficult to "read" the validity of a plate immediately after
        washout because clinging moisture can cause optical distortion. Your
        drying temp seems high. Specs sheet recommends 60-70 C. I'm not sure if
        that is the problem but lower the temp and see if that helps.

        Gerald
        http://BielerPress.blogspot.com



        On 12/3/12 1:58 PM, tinglado_letterpress wrote:
        > Dear list members,
        >
        > I am using KF95 PP, processing the plate as follows: exposure: 200 s, wash out: 240 s / 21 ºC, dry out: 10 min at 80 ºC and post exposure 300 s.
        >
        > The main problem is that some letters (body size 6 pt) are pushed out of its possition in the PP. Please, check this picture to see what I mean (http://flic.kr/p/dyigw8). I checked it after wash out and they seem to be at the correct position. Do you think that it could be something related to the dry out process? Do you think that a bit of back exposure could fix the exposed photopolymer to the plastic base?
        >
        > The problem only happens with the '1' and the 'l' characters.
        >
        > I am in trouble, because it happens every time I try to process this work.
        >
        > Please, help!!!! :-)
        >
        > Thank you in advance and regards,
        >




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        --
        María Dolores Jiménez

      • letterpress_man
        Lola I use the same plates as you are using, I buy them from Boxcar Press and they recomend 25 sec back exposure. They sell and process probibly more plates
        Message 3 of 12 , Dec 3, 2012
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          Lola

          I use the same plates as you are using, I buy them from Boxcar Press and they recomend 25 sec back exposure. They sell and process probibly more plates than anyone one here so there advice should hold some weight. I also agree with the other comments Gerald made.

          Rick

          --- In PPLetterpress@yahoogroups.com, Mª Dolores Jiménez Mondragón <doloresj3@...> wrote:
          >
          > Thank you Gerald for you advices. I will try to improve those parts of the
          > process and I will be back with the results.
          >
          > Regards,
          >
          > Lola
          >
          >
          > 2012/12/3 Gerald Lange <Bieler@...>
          >
          > > Lola
          > >
          > > Your exposure time seems about right to me. But you really do need to
          > > test the exposure time with a 21 steps grey scale. With a hardness
          > > rating of 67 you should get a reading of 14-15 as solid—that means the
          > > 14-15 boxes are not washed out or corroded (13 or below should be washed
          > > out). Exposure times can vary dependent upon the condition of your
          > > bulbs/ballasts. Fine lines or dots might need a slightly longer exposure
          > > time.
          > >
          > > Basically, you are not giving enough time to build a decent structural
          > > relief if your exposure/washout are out of sync and imaging is drifting.
          > > You do not have to back-exposure this plate, the manufacturer has
          > > already done that.
          > >
          > > You washout can vary quite a bit dependent upon bath temp, machine,
          > > brushes, etc. Mainly you want a clean floor with no undercutting of the
          > > surface imaging.
          > >
          > > Post exposure should be the same or longer than the main exposure. I
          > > usually do about 1.5x.
          > >
          > > It is difficult to "read" the validity of a plate immediately after
          > > washout because clinging moisture can cause optical distortion. Your
          > > drying temp seems high. Specs sheet recommends 60-70 C. I'm not sure if
          > > that is the problem but lower the temp and see if that helps.
          > >
          > > Gerald
          > > http://BielerPress.blogspot.com
          > >
          > >
          > >
          > > On 12/3/12 1:58 PM, tinglado_letterpress wrote:
          > > > Dear list members,
          > > >
          > > > I am using KF95 PP, processing the plate as follows: exposure: 200 s,
          > > wash out: 240 s / 21 ºC, dry out: 10 min at 80 ºC and post exposure 300 s.
          > > >
          > > > The main problem is that some letters (body size 6 pt) are pushed out of
          > > its possition in the PP. Please, check this picture to see what I mean (
          > > http://flic.kr/p/dyigw8). I checked it after wash out and they seem to be
          > > at the correct position. Do you think that it could be something related to
          > > the dry out process? Do you think that a bit of back exposure could fix the
          > > exposed photopolymer to the plastic base?
          > > >
          > > > The problem only happens with the '1' and the 'l' characters.
          > > >
          > > > I am in trouble, because it happens every time I try to process this
          > > work.
          > > >
          > > > Please, help!!!! :-)
          > > >
          > > > Thank you in advance and regards,
          > > >
          > >
          > >
          > >
          > >
          > > ------------------------------------
          > >
          > > Yahoo! Groups Links
          > >
          > >
          > >
          > >
          >
          >
          > --
          > María Dolores Jiménez
          >
        • Gerald Lange
          Rick My understanding is that Boxcar recommends back-exposure only for the KF152 plate (the so called deep relief plate). Not the same animal as the KF95 or
          Message 4 of 12 , Dec 3, 2012
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            Rick

            My understanding is that Boxcar recommends back-exposure only for the
            KF152 plate (the so called deep relief plate). Not the same animal as
            the KF95 or the steel-backs KM95/KM152, which all have harder ratings.
            Specs for letterpress plates generally seem to indicate hardness ratings
            around 67. This, combined with its thickness, seems to plague the KF152.
            There have been a number of reported problems relating to loss of detail
            and drift and the solution proffered has been back exposure. Though it
            too is back-exposed by the manufacturer. Most sheet photopolymer is
            back-exposed prior to backing.

            My A&V rep told me the KF152 plate was made for molding purposes and
            recommended I not buy it for letterpress. He never steered me wrong so I
            follow his advice. I had a client who actually needed a thick molding
            plate, a polyester-backed plate with a thickness of .100" (the KF152 is
            .60"). It is softer as well and, except for its insane cost and poor
            shelf life, it is perfect for metal clay work and similar.

            Gerald


            On 12/3/12 3:05 PM, letterpress_man wrote:
            > Lola
            >
            > I use the same plates as you are using, I buy them from Boxcar Press and they recomend 25 sec back exposure. They sell and process probibly more plates than anyone one here so there advice should hold some weight. I also agree with the other comments Gerald made.
            >
            > Rick
            >
            > --- In PPLetterpress@yahoogroups.com, Mª Dolores Jiménez Mondragón<doloresj3@...> wrote:
            >> Thank you Gerald for you advices. I will try to improve those parts of the
            >> process and I will be back with the results.
            >>
            >> Regards,
            >>
            >> Lola
            >>
            >>
            >> 2012/12/3 Gerald Lange<Bieler@...>
            >>
            >>> Lola
            >>>
            >>> Your exposure time seems about right to me. But you really do need to
            >>> test the exposure time with a 21 steps grey scale. With a hardness
            >>> rating of 67 you should get a reading of 14-15 as solid—that means the
            >>> 14-15 boxes are not washed out or corroded (13 or below should be washed
            >>> out). Exposure times can vary dependent upon the condition of your
            >>> bulbs/ballasts. Fine lines or dots might need a slightly longer exposure
            >>> time.
            >>>
            >>> Basically, you are not giving enough time to build a decent structural
            >>> relief if your exposure/washout are out of sync and imaging is drifting.
            >>> You do not have to back-exposure this plate, the manufacturer has
            >>> already done that.
            >>>
            >>> You washout can vary quite a bit dependent upon bath temp, machine,
            >>> brushes, etc. Mainly you want a clean floor with no undercutting of the
            >>> surface imaging.
            >>>
            >>> Post exposure should be the same or longer than the main exposure. I
            >>> usually do about 1.5x.
            >>>
            >>> It is difficult to "read" the validity of a plate immediately after
            >>> washout because clinging moisture can cause optical distortion. Your
            >>> drying temp seems high. Specs sheet recommends 60-70 C. I'm not sure if
            >>> that is the problem but lower the temp and see if that helps.
            >>>
            >>> Gerald
            >>> http://BielerPress.blogspot.com
            >>>
            >>>
            >>>
            >>> On 12/3/12 1:58 PM, tinglado_letterpress wrote:
            >>>> Dear list members,
            >>>>
            >>>> I am using KF95 PP, processing the plate as follows: exposure: 200 s,
            >>> wash out: 240 s / 21 ºC, dry out: 10 min at 80 ºC and post exposure 300 s.
            >>>> The main problem is that some letters (body size 6 pt) are pushed out of
            >>> its possition in the PP. Please, check this picture to see what I mean (
            >>> http://flic.kr/p/dyigw8). I checked it after wash out and they seem to be
            >>> at the correct position. Do you think that it could be something related to
            >>> the dry out process? Do you think that a bit of back exposure could fix the
            >>> exposed photopolymer to the plastic base?
            >>>> The problem only happens with the '1' and the 'l' characters.
            >>>>
            >>>> I am in trouble, because it happens every time I try to process this
            >>> work.
            >>>> Please, help!!!! :-)
            >>>>
            >>>> Thank you in advance and regards,
            >>>>
          • letterpress_man
            Gerald When Boxcar switched me to the KF95 about 3 years ago from another plate they told me the only differance was I needed to back expose it for 25 sec,
            Message 5 of 12 , Dec 3, 2012
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              Gerald

              When Boxcar switched me to the KF95 about 3 years ago from another plate they told me the only differance was I needed to back expose it for 25 sec, been doing it all this time with great results on small type and fine lines. The only time I had a problem was when the imagesetter messed up on some small lines because of an exposure setting.


              Rick
              --- In PPLetterpress@yahoogroups.com, Gerald Lange <Bieler@...> wrote:
              >
              > Rick
              >
              > My understanding is that Boxcar recommends back-exposure only for the
              > KF152 plate (the so called deep relief plate). Not the same animal as
              > the KF95 or the steel-backs KM95/KM152, which all have harder ratings.
              > Specs for letterpress plates generally seem to indicate hardness ratings
              > around 67. This, combined with its thickness, seems to plague the KF152.
              > There have been a number of reported problems relating to loss of detail
              > and drift and the solution proffered has been back exposure. Though it
              > too is back-exposed by the manufacturer. Most sheet photopolymer is
              > back-exposed prior to backing.
              >
              > My A&V rep told me the KF152 plate was made for molding purposes and
              > recommended I not buy it for letterpress. He never steered me wrong so I
              > follow his advice. I had a client who actually needed a thick molding
              > plate, a polyester-backed plate with a thickness of .100" (the KF152 is
              > .60"). It is softer as well and, except for its insane cost and poor
              > shelf life, it is perfect for metal clay work and similar.
              >
              > Gerald
              >
              >
              > On 12/3/12 3:05 PM, letterpress_man wrote:
              > > Lola
              > >
              > > I use the same plates as you are using, I buy them from Boxcar Press and they recomend 25 sec back exposure. They sell and process probibly more plates than anyone one here so there advice should hold some weight. I also agree with the other comments Gerald made.
              > >
              > > Rick
              > >
              > > --- In PPLetterpress@yahoogroups.com, Mª Dolores Jiménez Mondragón<doloresj3@> wrote:
              > >> Thank you Gerald for you advices. I will try to improve those parts of the
              > >> process and I will be back with the results.
              > >>
              > >> Regards,
              > >>
              > >> Lola
              > >>
              > >>
              > >> 2012/12/3 Gerald Lange<Bieler@>
              > >>
              > >>> Lola
              > >>>
              > >>> Your exposure time seems about right to me. But you really do need to
              > >>> test the exposure time with a 21 steps grey scale. With a hardness
              > >>> rating of 67 you should get a reading of 14-15 as solid—that means the
              > >>> 14-15 boxes are not washed out or corroded (13 or below should be washed
              > >>> out). Exposure times can vary dependent upon the condition of your
              > >>> bulbs/ballasts. Fine lines or dots might need a slightly longer exposure
              > >>> time.
              > >>>
              > >>> Basically, you are not giving enough time to build a decent structural
              > >>> relief if your exposure/washout are out of sync and imaging is drifting.
              > >>> You do not have to back-exposure this plate, the manufacturer has
              > >>> already done that.
              > >>>
              > >>> You washout can vary quite a bit dependent upon bath temp, machine,
              > >>> brushes, etc. Mainly you want a clean floor with no undercutting of the
              > >>> surface imaging.
              > >>>
              > >>> Post exposure should be the same or longer than the main exposure. I
              > >>> usually do about 1.5x.
              > >>>
              > >>> It is difficult to "read" the validity of a plate immediately after
              > >>> washout because clinging moisture can cause optical distortion. Your
              > >>> drying temp seems high. Specs sheet recommends 60-70 C. I'm not sure if
              > >>> that is the problem but lower the temp and see if that helps.
              > >>>
              > >>> Gerald
              > >>> http://BielerPress.blogspot.com
              > >>>
              > >>>
              > >>>
              > >>> On 12/3/12 1:58 PM, tinglado_letterpress wrote:
              > >>>> Dear list members,
              > >>>>
              > >>>> I am using KF95 PP, processing the plate as follows: exposure: 200 s,
              > >>> wash out: 240 s / 21 ºC, dry out: 10 min at 80 ºC and post exposure 300 s.
              > >>>> The main problem is that some letters (body size 6 pt) are pushed out of
              > >>> its possition in the PP. Please, check this picture to see what I mean (
              > >>> http://flic.kr/p/dyigw8). I checked it after wash out and they seem to be
              > >>> at the correct position. Do you think that it could be something related to
              > >>> the dry out process? Do you think that a bit of back exposure could fix the
              > >>> exposed photopolymer to the plastic base?
              > >>>> The problem only happens with the '1' and the 'l' characters.
              > >>>>
              > >>>> I am in trouble, because it happens every time I try to process this
              > >>> work.
              > >>>> Please, help!!!! :-)
              > >>>>
              > >>>> Thank you in advance and regards,
              > >>>>
              >
            • Patricio Gatti
              Lola, como dice Gerald posiblemente tus lámparas pueden estar un poco agotadas, que platemaker tienes? cómo lavas? y cómo montas la película? Igual, la
              Message 6 of 12 , Dec 3, 2012
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                Lola, como dice Gerald posiblemente tus lámparas pueden estar un poco agotadas, que platemaker tienes? cómo lavas? y cómo montas la película? 
                Igual, la imagen que mandás es muy rara, nunca había visto que la letra se desplace... cuando falta luz el talud se estrecha y las líneas largas se desprenden y zigzaguean... vuelan los serif y los puntos... 
                En mi caso para los Jet de 0,94 le pongo 7 minutos de insoladora... tenemos dos platemakers distintos, uno italiano y otro argentino, y en ambos nos funciona el mismo tiempo, si las placas fueran miraclon con la mitad de tiempo en nuestros equipos está ok.
                (Para secar te recomiendo usar un secador de pelo antes del horno, 10' a 80º es mucho!, al final termino con 10', ahí lo que sobra no daña!)
                Conocés a mis amigos Plomez y a Lola Espinosa, hasta el momento eran mis colegas y amigos peninsulares?
                Salú, p
                 
                -----Original Message-----
                From: Gerald Lange <Bieler@...>
                To: PPLetterpress@yahoogroups.com
                Date: Mon, 03 Dec 2012 14:37:58 -0800
                Subject: Re: [PPLetterpress] Photopolymer with 'moving' parts

                Lola

                Your exposure time seems about right to me. But you really do need to
                test the exposure time with a 21 steps grey scale. With a hardness
                rating of 67 you should get a reading of 14-15 as solid—that means the
                14-15 boxes are not washed out or corroded (13 or below should be washed
                out). Exposure times can vary dependent upon the condition of your
                bulbs/ballasts. Fine lines or dots might need a slightly longer exposure
                time.

                Basically, you are not giving enough time to build a decent structural
                relief if your exposure/washout are out of sync and imaging is drifting.
                You do not have to back-exposure this plate, the manufacturer has
                already done that.

                You washout can vary quite a bit dependent upon bath temp, machine,
                brushes, etc. Mainly you want a clean floor with no undercutting of the
                surface imaging.

                Post exposure should be the same or longer than the main exposure. I
                usually do about 1.5x.

                It is difficult to "read" the validity of a plate immediately after
                washout because clinging moisture can cause optical distortion. Your
                drying temp seems high. Specs sheet recommends 60-70 C. I'm not sure if
                that is the problem but lower the temp and see if that helps.

                Gerald
                http://BielerPress.blogspot.com



                On 12/3/12 1:58 PM, tinglado_letterpress wrote:
                > Dear list members,
                >
                > I am using KF95 PP, processing the plate as follows: exposure: 200 s, wash out: 240 s / 21 ºC, dry out: 10 min at 80 ºC and post exposure 300 s.
                >
                > The main problem is that some letters (body size 6 pt) are pushed out of its possition in the PP. Please, check this picture to see what I mean ( http://flic.kr/p/dyigw8). I checked it after wash out and they seem to be at the correct position. Do you think that it could be something related to the dry out process? Do you think that a bit of back exposure could fix the exposed photopolymer to the plastic base?
                >
                > The problem only happens with the '1' and the 'l' characters.
                >
                > I am in trouble, because it happens every time I try to process this work.
                >
                > Please, help!!!! :-)
                >
                > Thank you in advance and regards,
                >




                ------------------------------------

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              • Gerald Lange
                Rick Have you ever tried NOT back-exposing the KF95 since you were switched over? A portion of my clients use the KF95s and they come out just as well as the
                Message 7 of 12 , Dec 3, 2012
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                  Rick

                  Have you ever tried NOT back-exposing the KF95 since you were switched
                  over? A portion of my clients use the KF95s and they come out just as
                  well as the steel-backed version (which you cannot obviously
                  back-expose.) Same processing times all around.

                  Trying to think out the back-exposure thing, which, as a practice, does
                  have to be done with liquid photopolymer, but is more of a hardening
                  procedure for mounting though. Personally, the practice seems odd to me
                  from a technical standpoint. With sheet photopolymer, the back-exposure
                  has to go through the polyester backing, an adhesive layer, and get
                  through the pre-existing back-exposure before it could have any effect.
                  Can't quite see it.

                  Gerald


                  On 12/3/12 4:14 PM, letterpress_man wrote:
                  > Gerald
                  >
                  > When Boxcar switched me to the KF95 about 3 years ago from another plate they told me the only differance was I needed to back expose it for 25 sec, been doing it all this time with great results on small type and fine lines. The only time I had a problem was when the imagesetter messed up on some small lines because of an exposure setting.
                  >
                  >
                  > Rick
                  > --- In PPLetterpress@yahoogroups.com, Gerald Lange<Bieler@...> wrote:
                  >> Rick
                  >>
                  >> My understanding is that Boxcar recommends back-exposure only for the
                  >> KF152 plate (the so called deep relief plate). Not the same animal as
                  >> the KF95 or the steel-backs KM95/KM152, which all have harder ratings.
                  >> Specs for letterpress plates generally seem to indicate hardness ratings
                  >> around 67. This, combined with its thickness, seems to plague the KF152.
                  >> There have been a number of reported problems relating to loss of detail
                  >> and drift and the solution proffered has been back exposure. Though it
                  >> too is back-exposed by the manufacturer. Most sheet photopolymer is
                  >> back-exposed prior to backing.
                  >>
                  >> My A&V rep told me the KF152 plate was made for molding purposes and
                  >> recommended I not buy it for letterpress. He never steered me wrong so I
                  >> follow his advice. I had a client who actually needed a thick molding
                  >> plate, a polyester-backed plate with a thickness of .100" (the KF152 is
                  >> .60"). It is softer as well and, except for its insane cost and poor
                  >> shelf life, it is perfect for metal clay work and similar.
                  >>
                  >> Gerald
                  >>
                  >>
                  >> On 12/3/12 3:05 PM, letterpress_man wrote:
                  >>> Lola
                  >>>
                  >>> I use the same plates as you are using, I buy them from Boxcar Press and they recomend 25 sec back exposure. They sell and process probibly more plates than anyone one here so there advice should hold some weight. I also agree with the other comments Gerald made.
                  >>>
                  >>> Rick
                  >>>
                  >>> --- In PPLetterpress@yahoogroups.com, Mª Dolores Jiménez Mondragón<doloresj3@> wrote:
                  >>>> Thank you Gerald for you advices. I will try to improve those parts of the
                  >>>> process and I will be back with the results.
                  >>>>
                  >>>> Regards,
                  >>>>
                  >>>> Lola
                  >>>>
                  >>>>
                  >>>> 2012/12/3 Gerald Lange<Bieler@>
                  >>>>
                  >>>>> Lola
                  >>>>>
                  >>>>> Your exposure time seems about right to me. But you really do need to
                  >>>>> test the exposure time with a 21 steps grey scale. With a hardness
                  >>>>> rating of 67 you should get a reading of 14-15 as solid—that means the
                  >>>>> 14-15 boxes are not washed out or corroded (13 or below should be washed
                  >>>>> out). Exposure times can vary dependent upon the condition of your
                  >>>>> bulbs/ballasts. Fine lines or dots might need a slightly longer exposure
                  >>>>> time.
                  >>>>>
                  >>>>> Basically, you are not giving enough time to build a decent structural
                  >>>>> relief if your exposure/washout are out of sync and imaging is drifting.
                  >>>>> You do not have to back-exposure this plate, the manufacturer has
                  >>>>> already done that.
                  >>>>>
                  >>>>> You washout can vary quite a bit dependent upon bath temp, machine,
                  >>>>> brushes, etc. Mainly you want a clean floor with no undercutting of the
                  >>>>> surface imaging.
                  >>>>>
                  >>>>> Post exposure should be the same or longer than the main exposure. I
                  >>>>> usually do about 1.5x.
                  >>>>>
                  >>>>> It is difficult to "read" the validity of a plate immediately after
                  >>>>> washout because clinging moisture can cause optical distortion. Your
                  >>>>> drying temp seems high. Specs sheet recommends 60-70 C. I'm not sure if
                  >>>>> that is the problem but lower the temp and see if that helps.
                  >>>>>
                  >>>>> Gerald
                  >>>>> http://BielerPress.blogspot.com
                  >>>>>
                  >>>>>
                  >>>>>
                  >>>>> On 12/3/12 1:58 PM, tinglado_letterpress wrote:
                  >>>>>> Dear list members,
                  >>>>>>
                  >>>>>> I am using KF95 PP, processing the plate as follows: exposure: 200 s,
                  >>>>> wash out: 240 s / 21 ºC, dry out: 10 min at 80 ºC and post exposure 300 s.
                  >>>>>> The main problem is that some letters (body size 6 pt) are pushed out of
                  >>>>> its possition in the PP. Please, check this picture to see what I mean (
                  >>>>> http://flic.kr/p/dyigw8). I checked it after wash out and they seem to be
                  >>>>> at the correct position. Do you think that it could be something related to
                  >>>>> the dry out process? Do you think that a bit of back exposure could fix the
                  >>>>> exposed photopolymer to the plastic base?
                  >>>>>> The problem only happens with the '1' and the 'l' characters.
                  >>>>>>
                  >>>>>> I am in trouble, because it happens every time I try to process this
                  >>>>> work.
                  >>>>>> Please, help!!!! :-)
                  >>>>>>
                  >>>>>> Thank you in advance and regards,
                  >>>>>>
                  >
                  >
                • Leslie Ross-Robertson
                  Hello: At Otis we recently had a similar problem after changing the bulbs out on platemaker, the Anderson Vreeland Rep suggested warming up the bulbs for 5:00
                  Message 8 of 12 , Dec 3, 2012
                  • 0 Attachment
                    Hello:

                    At Otis we recently had a similar problem after changing the bulbs out on platemaker, the Anderson Vreeland Rep suggested warming up the bulbs for 5:00 cycles before making plates for a month or so until there is even burn on the bulbs. He checked and found uneven bulb strength when exposing. We have had no problem since, warming up the bulbs up first. We do not back expose... after a couple of months after the bulbs have an even burn it should not be necessary. Perhaps you need to warm up the bulbs? Also check temp on the wash out.

                    Leslie
                    --- On Mon, 12/3/12, tinglado_letterpress <doloresj3@...> wrote:

                    From: tinglado_letterpress <doloresj3@...>
                    Subject: [PPLetterpress] Photopolymer with 'moving' parts
                    To: PPLetterpress@yahoogroups.com
                    Date: Monday, December 3, 2012, 9:58 PM

                     

                    Dear list members,

                    I am using KF95 PP, processing the plate as follows: exposure: 200 s, wash out: 240 s / 21 ºC, dry out: 10 min at 80 ºC and post exposure 300 s.

                    The main problem is that some letters (body size 6 pt) are pushed out of its possition in the PP. Please, check this picture to see what I mean (http://flic.kr/p/dyigw8). I checked it after wash out and they seem to be at the correct position. Do you think that it could be something related to the dry out process? Do you think that a bit of back exposure could fix the exposed photopolymer to the plastic base?

                    The problem only happens with the '1' and the 'l' characters.

                    I am in trouble, because it happens every time I try to process this work.

                    Please, help!!!! :-)

                    Thank you in advance and regards,

                    --
                    Lola

                  • Harold Kyle
                    ...and yet, it works! I know you and I have debated this in the past. :) I know that Boxcar Press would not be able to hold such fine detail without a short
                    Message 9 of 12 , Dec 3, 2012
                    • 0 Attachment
                      ...and yet, it works! I know you and I have debated this in the past. :)

                      I know that Boxcar Press would not be able to hold such fine detail without a short back exposure. Our sales rep for Toyobo photopolymer plates, if I'm not mistaken, recommended it to us in the first place. It makes perfect sense to me why this would keep fine dots and lines firmly attached to the base of the plate. 

                      But to each their own, and why add complexity if you're happy without?! 

                      Thanks
                      Harold


                      On Mon, Dec 3, 2012 at 7:47 PM, Gerald Lange <Bieler@...> wrote:
                      Rick

                      Have you ever tried NOT back-exposing the KF95 since you were switched
                      over? A portion of my clients use the KF95s and they come out just as
                      well as the steel-backed version (which you cannot obviously
                      back-expose.) Same processing times all around.

                      Trying to think out the back-exposure thing, which, as a practice, does
                      have to be done with liquid photopolymer, but is more of a hardening
                      procedure for mounting though. Personally, the practice seems odd to me
                      from a technical standpoint. With sheet photopolymer, the back-exposure
                      has to go through the polyester backing, an adhesive layer, and get
                      through the pre-existing back-exposure before it could have any effect.
                      Can't quite see it.

                      Gerald


                      On 12/3/12 4:14 PM, letterpress_man wrote:
                      > Gerald
                      >
                      > When Boxcar switched me to the KF95 about 3 years ago from another plate they told me the only differance was I needed to back expose it for 25 sec, been doing it all this time with great results on small type and fine lines.  The only time I had a problem was when the imagesetter messed up on some small lines because of an exposure setting.
                      >
                      >
                      > Rick
                      > --- In PPLetterpress@yahoogroups.com, Gerald Lange<Bieler@...>  wrote:
                      >> Rick
                      >>
                      >> My understanding is that Boxcar recommends back-exposure only for the
                      >> KF152 plate (the so called deep relief plate). Not the same animal as
                      >> the KF95 or the steel-backs KM95/KM152, which all have harder ratings.
                      >> Specs for letterpress plates generally seem to indicate hardness ratings
                      >> around 67. This, combined with its thickness, seems to plague the KF152.
                      >> There have been a number of reported problems relating to loss of detail
                      >> and drift and the solution proffered has been back exposure. Though it
                      >> too is back-exposed by the manufacturer. Most sheet photopolymer is
                      >> back-exposed prior to backing.
                      >>
                      >> My A&V rep told me the KF152 plate was made for molding purposes and
                      >> recommended I not buy it for letterpress. He never steered me wrong so I
                      >> follow his advice. I had a client who actually needed a thick molding
                      >> plate, a polyester-backed plate with a thickness of .100" (the KF152 is
                      >> .60"). It is softer as well and, except for its insane cost and poor
                      >> shelf life, it is perfect for metal clay work and similar.
                      >>
                      >> Gerald
                      >>
                      >>
                      >> On 12/3/12 3:05 PM, letterpress_man wrote:
                      >>> Lola
                      >>>
                      >>> I use the same plates as you are using, I buy them from Boxcar Press and they recomend 25 sec back exposure.  They sell and process probibly more plates than anyone one here so there advice should hold some weight.  I also agree with the other comments Gerald made.
                      >>>
                      >>> Rick
                      >>>
                      >>> --- In PPLetterpress@yahoogroups.com, Mª Dolores Jiménez Mondragón<doloresj3@>   wrote:
                      >>>> Thank you Gerald for you advices. I will try to improve those parts of the
                      >>>> process and I will be back with the results.
                      >>>>
                      >>>> Regards,
                      >>>>
                      >>>> Lola
                      >>>>
                      >>>>
                      >>>> 2012/12/3 Gerald Lange<Bieler@>
                      >>>>
                      >>>>> Lola
                      >>>>>
                      >>>>> Your exposure time seems about right to me. But you really do need to
                      >>>>> test the exposure time with a 21 steps grey scale. With a hardness
                      >>>>> rating of 67 you should get a reading of 14-15 as solid—that means the
                      >>>>> 14-15 boxes are not washed out or corroded (13 or below should be washed
                      >>>>> out). Exposure times can vary dependent upon the condition of your
                      >>>>> bulbs/ballasts. Fine lines or dots might need a slightly longer exposure
                      >>>>> time.
                      >>>>>
                      >>>>> Basically, you are not giving enough time to build a decent structural
                      >>>>> relief if your exposure/washout are out of sync and imaging is drifting.
                      >>>>> You do not have to back-exposure this plate, the manufacturer has
                      >>>>> already done that.
                      >>>>>
                      >>>>> You washout can vary quite a bit dependent upon bath temp, machine,
                      >>>>> brushes, etc. Mainly you want a clean floor with no undercutting of the
                      >>>>> surface imaging.
                      >>>>>
                      >>>>> Post exposure should be the same or longer than the main exposure. I
                      >>>>> usually do about 1.5x.
                      >>>>>
                      >>>>> It is difficult to "read" the validity of a plate immediately after
                      >>>>> washout because clinging moisture can cause optical distortion. Your
                      >>>>> drying temp seems high. Specs sheet recommends 60-70 C. I'm not sure if
                      >>>>> that is the problem but lower the temp and see if that helps.
                      >>>>>
                      >>>>> Gerald
                      >>>>> http://BielerPress.blogspot.com
                      >>>>>
                      >>>>>
                      >>>>>
                      >>>>> On 12/3/12 1:58 PM, tinglado_letterpress wrote:
                      >>>>>> Dear list members,
                      >>>>>>
                      >>>>>> I am using KF95 PP, processing the plate as follows: exposure: 200 s,
                      >>>>> wash out: 240 s / 21 ºC, dry out: 10 min at 80 ºC and post exposure 300 s.
                      >>>>>> The main problem is that some letters (body size 6 pt) are pushed out of
                      >>>>> its possition in the PP. Please, check this picture to see what I mean (
                      >>>>> http://flic.kr/p/dyigw8). I checked it after wash out and they seem to be
                      >>>>> at the correct position. Do you think that it could be something related to
                      >>>>> the dry out process? Do you think that a bit of back exposure could fix the
                      >>>>> exposed photopolymer to the plastic base?
                      >>>>>> The problem only happens with the '1' and the 'l' characters.
                      >>>>>>
                      >>>>>> I am in trouble, because it happens every time I try to process this
                      >>>>> work.
                      >>>>>> Please, help!!!! :-)
                      >>>>>>
                      >>>>>> Thank you in advance and regards,
                      >>>>>>
                      >
                      >




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                      --
                      Boxcar Press
                      509 W. Fayette St. #135
                      Syracuse, NY  13204

                    • Gerald Lange
                      Hi Leslie Besides simply following manufacturer data for plate processing, I d think that a lot of practices like this go a long way in helping to provide a
                      Message 10 of 12 , Dec 4, 2012
                      • 0 Attachment
                        Hi Leslie

                        Besides simply following manufacturer data for plate processing, I'd think that a lot of practices like this go a long way in helping to provide a modicum of regularly in producing successful plates.

                        Warming up the area and raw stock to room temperature, running an initial false exposure (to heat the bulbs), as well as a false washout (to soften the brushes and distribute bath heat), waiting for the plates to cool down before post-exposure, etc., should result in consistent results throughout the day's work.

                        It doesn't hurt at all to be fairly routine in maintenance of the machine: draining and flushing the bath religiously, keeping the bath clean of build up, lubrication, etc. Other practices should be regular monitoring of plate production for subtle changes, checking exposure rates of the bulbs and examining the bulbs (and ballasts) for inconsistencies, keeping the brush tufts stiff and straight and the brush plate free of hardened waste, replacing the Kreene at the first incident of possible problems from dirt or scratches or difficulty in quickly obtaining sure vacuum, etc., etc.

                        There aren't really any special tricks to this, just a matter of keeping house, so to speak. And, it keeps the voodoo at bay.

                        Gerald



                        --- In PPLetterpress@yahoogroups.com, Leslie Ross-Robertson <modernoptic@...> wrote:
                        >
                        > Hello:
                        >
                        > At Otis we recently had a similar problem after changing the bulbs out on platemaker, the Anderson Vreeland Rep suggested warming up the bulbs for 5:00 cycles before making plates for a month or so until there is even burn on the bulbs. He checked and found uneven bulb strength when exposing. We have had no problem since, warming up the bulbs up first. We do not back expose... after a couple of months after the bulbs have an even burn it should not be necessary. Perhaps you need to warm up the bulbs? Also check temp on the wash out.
                        >
                        > Leslie
                        > --- On Mon, 12/3/12, tinglado_letterpress <doloresj3@...> wrote:
                        >
                        > From: tinglado_letterpress <doloresj3@...>
                        > Subject: [PPLetterpress] Photopolymer with 'moving' parts
                        > To: PPLetterpress@yahoogroups.com
                        > Date: Monday, December 3, 2012, 9:58 PM
                        >
                        >
                        >
                        >
                        >
                        >
                        >
                        >
                        >
                        >
                        >
                        >
                        >
                        >
                        >
                        >
                        >  
                        >
                        >
                        >
                        >
                        >
                        >
                        >
                        >
                        >
                        > Dear list members,
                        >
                        >
                        >
                        > I am using KF95 PP, processing the plate as follows: exposure: 200 s, wash out: 240 s / 21 ºC, dry out: 10 min at 80 ºC and post exposure 300 s.
                        >
                        >
                        >
                        > The main problem is that some letters (body size 6 pt) are pushed out of its possition in the PP. Please, check this picture to see what I mean (http://flic.kr/p/dyigw8). I checked it after wash out and they seem to be at the correct position. Do you think that it could be something related to the dry out process? Do you think that a bit of back exposure could fix the exposed photopolymer to the plastic base?
                        >
                        >
                        >
                        > The problem only happens with the '1' and the 'l' characters.
                        >
                        >
                        >
                        > I am in trouble, because it happens every time I try to process this work.
                        >
                        >
                        >
                        > Please, help!!!! :-)
                        >
                        >
                        >
                        > Thank you in advance and regards,
                        >
                        >
                        >
                        > --
                        >
                        > Lola
                        >
                      • Leslie Ross-Robertson
                        Hello Gerald: I completely agree! The less voodoo the better... Leslie ... From: Gerald Lange Subject: [PPLetterpress] Re: Photopolymer with
                        Message 11 of 12 , Dec 4, 2012
                        • 0 Attachment
                          Hello Gerald:

                          I completely agree! The less voodoo the better...

                          Leslie

                          --- On Tue, 12/4/12, Gerald Lange <Bieler@...> wrote:

                          From: Gerald Lange <Bieler@...>
                          Subject: [PPLetterpress] Re: Photopolymer with 'moving' parts
                          To: PPLetterpress@yahoogroups.com
                          Date: Tuesday, December 4, 2012, 9:09 AM

                           

                          Hi Leslie

                          Besides simply following manufacturer data for plate processing, I'd think that a lot of practices like this go a long way in helping to provide a modicum of regularly in producing successful plates.

                          Warming up the area and raw stock to room temperature, running an initial false exposure (to heat the bulbs), as well as a false washout (to soften the brushes and distribute bath heat), waiting for the plates to cool down before post-exposure, etc., should result in consistent results throughout the day's work.

                          It doesn't hurt at all to be fairly routine in maintenance of the machine: draining and flushing the bath religiously, keeping the bath clean of build up, lubrication, etc. Other practices should be regular monitoring of plate production for subtle changes, checking exposure rates of the bulbs and examining the bulbs (and ballasts) for inconsistencies, keeping the brush tufts stiff and straight and the brush plate free of hardened waste, replacing the Kreene at the first incident of possible problems from dirt or scratches or difficulty in quickly obtaining sure vacuum, etc., etc.

                          There aren't really any special tricks to this, just a matter of keeping house, so to speak. And, it keeps the voodoo at bay.

                          Gerald

                          --- In PPLetterpress@yahoogroups.com, Leslie Ross-Robertson <modernoptic@...> wrote:
                          >
                          > Hello:
                          >
                          > At Otis we recently had a similar problem after changing the bulbs out on platemaker, the Anderson Vreeland Rep suggested warming up the bulbs for 5:00 cycles before making plates for a month or so until there is even burn on the bulbs. He checked and found uneven bulb strength when exposing. We have had no problem since, warming up the bulbs up first. We do not back expose... after a couple of months after the bulbs have an even burn it should not be necessary. Perhaps you need to warm up the bulbs? Also check temp on the wash out.
                          >
                          > Leslie
                          > --- On Mon, 12/3/12, tinglado_letterpress <doloresj3@...> wrote:
                          >
                          > From: tinglado_letterpress <doloresj3@...>
                          > Subject: [PPLetterpress] Photopolymer with 'moving' parts
                          > To: PPLetterpress@yahoogroups.com
                          > Date: Monday, December 3, 2012, 9:58 PM
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >  
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          > Dear list members,
                          >
                          >
                          >
                          > I am using KF95 PP, processing the plate as follows: exposure: 200 s, wash out: 240 s / 21 ºC, dry out: 10 min at 80 ºC and post exposure 300 s.
                          >
                          >
                          >
                          > The main problem is that some letters (body size 6 pt) are pushed out of its possition in the PP. Please, check this picture to see what I mean (http://flic.kr/p/dyigw8). I checked it after wash out and they seem to be at the correct position. Do you think that it could be something related to the dry out process? Do you think that a bit of back exposure could fix the exposed photopolymer to the plastic base?
                          >
                          >
                          >
                          > The problem only happens with the '1' and the 'l' characters.
                          >
                          >
                          >
                          > I am in trouble, because it happens every time I try to process this work.
                          >
                          >
                          >
                          > Please, help!!!! :-)
                          >
                          >
                          >
                          > Thank you in advance and regards,
                          >
                          >
                          >
                          > --
                          >
                          > Lola
                          >

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