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Making Negative for Photopolymer Plates

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  • Katey Lady
    Hi Jan- You need to send your file to a service bureau and have it outputted onto photographic film with an Imagesetter. Make sure your file is all black and
    Message 1 of 11 , Feb 23, 2011

      Hi Jan-

      You need to send your file to a service bureau and have it outputted onto photographic film with an Imagesetter. Make sure your file is all black and white (well, you can fiddle with halftones if you like but letterpress is better suited for line art), and at least 600 dpi resolution. You do not need to invert the colors, that will happen when it is sent through the Imagesetter. When you give the file to the service bureau, ask for the film to be "right reading, emulsion up." Best to let them know how you will be making the plate and printing it- I usually ask for "RREU for letterpress" and they know what I want.

      The transparancys you can run through your home laser printer is not opaque enough to allow for quality letterpress plates to be made. There are lots of tips and tricks and schemes and gadgets for making film at home, but I say save yourself the trouble, and wasted plate material from bad film, and find a professional to make it. I pay $15 + shipping per 8 1/2 x 11 sheet of always perfect film.

      Good luck,

      -Katey
    • Eric
      ... It needs to be in Bitmap mode. You could send a file in greyscale mode that just had two levels, black and white, but the image would still get screened
      Message 2 of 11 , Feb 23, 2011
        --- In PPLetterpress@yahoogroups.com, Katey Lady <crazyprettybird@...> wrote:

        >Make sure your file is all black and white

        It needs to be in Bitmap mode. You could send a file in greyscale mode that just had two levels, black and white, but the image would still get screened at the imagesetter, and give dotted edges.

        Eric Holub, SF
      • Peter Fraterdeus
        ... Or in Vector Mode. Adobe Illustrator has a very useful function called Recolor Artwork (Under Edit/Edit Colors/Recolor with Preset ) which will find all
        Message 3 of 11 , Feb 23, 2011
          On 23 Feb 2011, at 9:42 AM, Eric wrote:
          > --- In PPLetterpress@yahoogroups.com, Katey Lady <crazyprettybird@...> wrote:
          >
          >> Make sure your file is all black and white
          >
          > It needs to be in Bitmap mode. You could send a file in greyscale mode that just had two levels, black and white, but the image would still get screened at the imagesetter, and give dotted edges.
          >
          > Eric Holub, SF


          Or in Vector Mode.

          Adobe Illustrator has a very useful function called "Recolor Artwork" (Under "Edit/Edit Colors/Recolor with Preset") which will find all the variations of colors in the document (select the objects to recolor first) and boil them down to exactly two (or three or whatever, if you are doing separations). I use Recolor with Preset and choose the Pantone Solid Uncoated "Color Library" to limit the swatches to known Pantone Colors.

          I use this to massage client supplied artwork before getting film made. If people don't know to use only spot colors (not CMYK process definitions), it's easy to end up with a real mess of wasted film before getting what you need.

          Cheers!

          peter

          Peter Fraterdeus
          Exquisite letterpress takes timeā„¢
          http://slowprint.com/

          IdeasWords : Idea Swords
          Communication Strategy
          Semiotx.com @ideaswords
        • Jan Kellett
          Thanks to all for your advice. I live on the west coast of Canada and have been sending to Boxcar (very good) for plate processing - thousands of miles - so
          Message 4 of 11 , Feb 24, 2011
            Thanks to all for your advice. I live on the west coast of Canada and have been sending to Boxcar (very good) for plate processing - thousands of miles - so want to process my own plates if I can. I think I've found a bureau on the island that will do what I need for the film. I thought I could make the negatives, but my printer is not up to the job.
            Jan
          • VeronicaV
            Hi Jan, I live in Seattle and get mine done at http://www.ckgraphics.com/ They are pretty quick, and will probably send you the negatives and it won t be as
            Message 5 of 11 , Feb 25, 2011
              Hi Jan,

              I live in Seattle and get mine done at http://www.ckgraphics.com/
              They are pretty quick, and will probably send you the negatives and it won't be as far as New York.

              I've also bought film from elum and I know they do negatives and plate making services and they are in California.


              Hope this helps,
              Veronica

              --- In PPLetterpress@yahoogroups.com, Jan Kellett <jan.kellett@...> wrote:
              >
              > Thanks to all for your advice. I live on the west coast of Canada and have been sending to Boxcar (very good) for plate processing - thousands of miles - so want to process my own plates if I can. I think I've found a bureau on the island that will do what I need for the film. I thought I could make the negatives, but my printer is not up to the job.
              > Jan
              >
            • Rod
              Have you folks looked in to producing your own negatives? Twelve years ago when we switched to digital plates, we couldn t give away our NuArc process camera
              Message 6 of 11 , Feb 25, 2011
                Have you folks looked in to producing your own negatives? Twelve years ago when we switched to digital plates, we couldn't give away our
                NuArc process camera and flip top platemaker. We junked it just to get more space in our shop.

                Talk to a few local print shops and you may score a camera for little or nothing. Both rapid access and lith film are available from <http://www.valleylitho.com/acatalog/Valley_Litho_Supply_Film_5.html> , a source we have had excellent results with.

                Sheet photopolymers are more light sensitive and have a such short exposure latitude that using negatives produced on a laser printer don't have enough density. However, we have excellent results with liquid photopolymers using negatives made a laser printer. We imprint wooden tokens on a C&P with dies made with liquid photopolymer.

                <http://www.youtube.com/watch?v=MvOKy3Msa4I> is one of my casting videos on YouTube that shows another use for liquid photopolymer.

                Have fun!

                Rod
              • Eric
                ... Is this because only some of the exposure is through the negative, and the rest through the back of the liquid? Or does the liquid have a different
                Message 7 of 11 , Feb 25, 2011
                  --- In PPLetterpress@yahoogroups.com, "Rod" <granthams@...> wrote:
                  >

                  > Sheet photopolymers are more light sensitive and have a such short exposure latitude that using negatives produced on a laser printer don't have enough density. However, we have excellent results with liquid photopolymers using negatives made a laser printer. We imprint wooden tokens on a C&P with dies made with liquid photopolymer.
                  >

                  Is this because only some of the exposure is through the negative, and the rest through the back of the liquid? Or does the liquid have a different exposure latitude?
                  What is your experience with shelf-life, both raw liquid and processed material? I have a processed sample of Merigraph liquid photopolymer that is still supple and it is over twenty years old (but never exposed to ink or solvent).
                  Eric Holub, SF
                • John Risseeuw
                  I talked to a guy at Freestyle Photo in L.A. today and he said that orthochromatic film is no longer being made and they have none to sell. Konica had been
                  Message 8 of 11 , Feb 25, 2011
                    I talked to a guy at Freestyle Photo in L.A. today and he said that
                    orthochromatic film is no longer being made and they have none to sell.
                    Konica had been making it and Freestyle sold it under the Arista label. It's
                    gone. I have taught a photo processes course here at Arizona State
                    University for 30 years, making films in a process camera darkroom for photo
                    printmaking, and I can no longer teach it. We do make photopolymer plates
                    using other methods, but it was always good to fall back on dense, crisp
                    darkroom films.

                    The lack of availability of ortho film may soon impinge on service bureaus
                    with Imagesetters, although there is a company still making film for them,
                    apparently. I hope someone soon comes up with a better process for digitally
                    printed films that are opaque and sharp.

                    John


                    On 2/25/11 12:20 PM, "Rod" <granthams@...> wrote:

                    >
                    > Have you folks looked in to producing your own negatives? Twelve years ago
                    > when we switched to digital plates, we couldn't give away our
                    > NuArc process camera and flip top platemaker. We junked it just to get more
                    > space in our shop.
                    >
                    > Talk to a few local print shops and you may score a camera for little or
                    > nothing. Both rapid access and lith film are available from
                    > <http://www.valleylitho.com/acatalog/Valley_Litho_Supply_Film_5.html> , a
                    > source we have had excellent results with.
                    >
                    > Sheet photopolymers are more light sensitive and have a such short exposure
                    > latitude that using negatives produced on a laser printer don't have enough
                    > density. However, we have excellent results with liquid photopolymers using
                    > negatives made a laser printer. We imprint wooden tokens on a C&P with dies
                    > made with liquid photopolymer.
                    >
                    > <http://www.youtube.com/watch?v=MvOKy3Msa4I> is one of my casting videos on
                    > YouTube that shows another use for liquid photopolymer.
                    >
                    > Have fun!
                    >
                    > Rod
                    >
                    >
                    >
                    > ------------------------------------
                    >
                    > Yahoo! Groups Links
                    >
                    >
                    >
                  • Rod
                    ... Liquid photopolymer has a much greater exposure latitude. As a trial we left some on a shelf for about 5 years and noticed that exposure times had to be
                    Message 9 of 11 , Feb 25, 2011
                      > > Sheet photopolymers are more light sensitive and have a such short exposure latitude that using negatives produced on a laser printer don't have enough density. However, we have excellent results with liquid photopolymers using negatives made a laser printer. We imprint wooden tokens on a C&P with dies made with liquid photopolymer.
                      > >
                      >
                      > Is this because only some of the exposure is through the negative, and the rest through the back of the liquid? Or does the liquid have a different exposure latitude?
                      > What is your experience with shelf-life, both raw liquid and processed material? I have a processed sample of Merigraph liquid photopolymer that is still supple and it is over twenty years old (but never exposed to ink or solvent).
                      > Eric Holub, SF
                      >
                      Liquid photopolymer has a much greater exposure latitude. As a trial we left some on a shelf for about 5 years and noticed that exposure times had to be increased from 1 minute to 1 minute 45 seconds through the base on the older material. Our normal exposure time using F20T12BLB fluorscent bulbs is 1 minute base, 2 minutes through the negative with a 5 minute in-water post exposure. Our lights are about 3 inches away from the negative.

                      The finished die tends to yellow with age, but doesn't seem to deteriorate. We've been using both sheet and liquid photopolymers since 1982. Both the total thickness and relief depth are easily controlled with liquid photopolymers.

                      Since the printing plates we need in my print shop are usually less than 10 square inches, scrub out is done in the sink. Liquid photopolymer scrubs out in less than a minute, compared to about 5 minutes for sheet photopolymer which we seldom use. Hard liquid (95 durometer) works as well for making stamp matrix as metal backed hard sheet.

                      In no way am I discouraging the use of hard sheet photopolymer, but in our applications the liquid is more practical.

                      Rod
                    • Jan Kellett
                      Thanks, Veronica, part of the problem is customs so I wanted to get somewhere in Canada. I think I ve found a bureau not too far from where I live, so can cut
                      Message 10 of 11 , Feb 26, 2011
                        Thanks, Veronica, part of the problem is customs so I wanted to get somewhere in Canada. I think I've found a bureau not too far from where I live, so can cut out the middle men (customs, USP and Canada Post), at least for the negatives. I think for me making the negatives is a bridge too far, certainly at the moment. I print, illustrate and bind too, and the processes are taking over the mad-house :-)
                        Jan
                      • Yvon
                        Jan, there are at least 4 service providers in Vancouver alone that run film every week, if not everyday. Feel free to contact me for more info. I can also
                        Message 11 of 11 , Feb 27, 2011
                          Jan, there are at least 4 service providers in Vancouver alone that run film every week, if not everyday. Feel free to contact me for more info. I can also give you the name of a graphic supplier on the Island that might know someone even closer to you.
                          Regards, Yvon

                          --- In PPLetterpress@yahoogroups.com, Jan Kellett <jan.kellett@...> wrote:
                          >
                          > Thanks, Veronica, part of the problem is customs so I wanted to get somewhere in Canada. I think I've found a bureau not too far from where I live, so can cut out the middle men (customs, USP and Canada Post), at least for the negatives. I think for me making the negatives is a bridge too far, certainly at the moment. I print, illustrate and bind too, and the processes are taking over the mad-house :-)
                          > Jan
                          >
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