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  • Standard ink densities?

    Just received a third party process swatch book. In the book it lists the densities that the job was run at. They are:

    K: 1.90
    C: 1.45
    M: 1.50
    Y: 0.95

    Are these standard numbers? If not, what are standard numbers, or is this simply to vague of a question?

    To be honest I know little on this topic.

  • #2
    Re: Standard ink densities?

    If you look at page 21, Section 6.2, of "G7_how-to_v6[final]" freely downoadable from www.gracol.org, although solids are to be run to Lab aim values, approximate Status T densities are listed:
    C 1.45 +/- 0.10
    M 1.45 +/- 0.10
    Y 1.0 +/- 0.07
    K 1.7 + 0.2 - 0.05

    So the densities you listed are within that tolerance. Next would be to check TVI, but since TVI is obtained from colorimetry in GRACoL2006_Coated1, then the TVI values are gonna be different than TVI obtained from densitometry. To get TVI values obtained from densitometry, you'll need to purchase ISO 12647-2. Note: Solids for GRACoL2006_Coated1 are the same as ISO 12647-2 solid Lab values.

    Don

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    • #3
      Re: Standard ink densities?

      Thanks, Don.

      I must admit, alot of what you mention is over my head. I have no idea what TVI is, but I am in the process of printing that Gracol doc you mention and will have a read.

      Thanks again.

      Comment


      • #4
        Re: Standard ink densities?

        TVI is the dot gain. It is irrelevant for measuring total ink density on a solid swatch. The numbers from Gracol are the results from their given ink and paper. I found that all of these recommended densities worked except cyan which was closer at a density of 138. This was based on Kohl-Madden Spectrum series ink on Sterling Ultra stock. The way for a printer to determine the printing density is run a variety of densities and take lab readings using a densitometer. The density that comes closest to the target is what you should run to. This will vary by ink and paper combination.

        If you are refering to the Pantone swatch guides that list the densities that the book was created with, I would be skeptical. Take an actual reading of the book with your densitometer and will find that these numbers will vary greatly. Of the course the designer that is thinking the swatch book is blessed by God himself doesn't understand all of this.

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        • #5
          Re: Standard ink densities?

          The values you have mentioned are what we use for coated paper.
          Does anyone have the values for uncoated paper??
          We use
          C-110
          M-110
          Y-95
          K-130

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          • #6
            Re: Standard ink densities?

            The standard ISO 12647-2 does not define valuables of density. Only Lab. defines values
            It is necessary to accomplish a test of inky to define correct the values of density at each workshop. These varied in terms of ink, the paper, etc ...

            Pardon for my very bad English.

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            • #7
              Re: Standard ink densities?

              Hi Gregg,

              IMHO, your standard densities can be can be of any value. As long as it gives you a color gamut that is big (hopefully bigger than ISO 12647-2) and that it is gray balanced, and that your CMYK solids are within Delta E of 5.

              Once you get your Delta E within the limit, measure now your solids and check your density value per color (CMYK).

              These new values are now your personalized standard densities for that particular set of ink and paper. To be on the safe side, you may want to cross check whether the same density values can also be applied when you change any of your materials (ink, paper weight, etc.).

              Hope this helps.

              Larry

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              • #8
                Re: Standard ink densities?

                > {quote:title=ian wrote:}{quote}
                > The values you have mentioned are what we use for coated paper.
                > Does anyone have the values for uncoated paper??
                > We use
                > C-110
                > M-110
                > Y-95
                > K-130

                Hi Ian,

                Sorry to but in, but do you have values for running Matt/Satin stocks?

                cheers!

                dwane

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                • #9
                  Re: Standard ink densities?

                  I am agree with Larry, the choice of standard density and tolernce very costumized depend on the quality of ink (purity, hue error, and rich gamut). Ink level has a density absolute, we put optimum level where no set-off, printthrough. And when it's printed on stock has a specific absorp, we called ink dry back. If we refer on ISO 12647-2, we must set ink, paper, and ink level as certain setting, make sure all combination standard. But dont forget think about TVI, because optical dotgain from penetrate oil was a problem too.

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                  • #10
                    Re: Standard ink densities?

                    we use on uncoated
                    C-90
                    M-90
                    Y-90
                    K-125

                    coated
                    C-125
                    M-125
                    Y-110
                    K-160

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                    • #11
                      Re: Standard ink densities?

                      Optimum density for ink is determined by measuring the amount of contrast obtained in the 3/4 tone. When you are printing to maximum contrast you will have the highest obtainable color saturation for the color without plugging the half-tones. This will give you the largest color gamut for your ink set.

                      It will likely be necessary to curve your plates in order to maintain gray balance throughout the tonal range.

                      Standard densities I commonly see in heatset pressrooms -

                      K - 1.65
                      C - 1.35
                      M - 1.45
                      Y - .95

                      + - .05

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                      • #12
                        Re: Standard ink densities?

                        The reference solid ink densities for uncoated are (based on Gracol 6) -
                        Y. 95
                        M 1.12
                        C 1.00
                        K 1.25
                        These are DRY numbers wet are about + .07 for C-M-Y and +.15 for black.
                        A "secret" is to develop plate curves so that uncoated prints the same dot gain as coated - the color is excellent!
                        Dan Remaley
                        412.259.1814

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                        • #13
                          Re: Standard ink densities?

                          1.- the ink should be in values Lab that they correspond to each color and those are according to the iso 2846-1
                          2.- the substratum should be so that we talked about the standard
                          3.- they try on the fast colors when printing and should be his moral values Lab according to the board of the standard
                          4.- having right now those valuables we initiated the measurement in the 80 % to obtain the best relative contrast
                          5.- we will by default have the optimal densities of the colors CMYK.

                          1.- la tinta debe estar en los valores Lab que corresponden a cada color y esos son según la iso 2846-1
                          2.- el sustrato debe estar según lo que hablamos de la norma.
                          3.- al imprimir se miden los colores sólidos y deben estar sus valores Lab según la tabla de la norma
                          4.- teniendo ya esos valores iniciamos la medición en el 80% para obtener el mejor contraste relativo
                          5.- por consecuencia tendremos las densidades óptimas de la cuatricromía.

                          Saludos

                          Douglas
                          www.tecnografico.cl

                          Comment


                          • #14
                            Re: Standard ink densities?

                            Ink density readings are heavily effected by the emulsion forming properties of your ink and water or the transfer capabilities of waterless inks.
                            Depending on the void size or white spaces between the transferred ink and or ink-water emulsion to substrate there can be a huge difference in density readings and yet a lower density can appear to be darker and or more saturated than a higher density reading.

                            Look at a solid with a 50 to 75 power magnifier and look at the spaces(white area) between the transferred ink film.

                            If the spaces are almost non existent your densitometer will reading light reflected mostly from the ink and not the white area between the transferred ink film.

                            If the spaces are easily noticeable you will have to carry a heavier ink film to compensate for the spaces between the ink particles to get a similar density reading.

                            Edited by: Pat Berger on Jul 16, 2008 6:29 AM

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                            • #15
                              Wouldn't a standard density also depend on what kinds of proofs you use? For example, if you have and inkjet proof and a KA proof, they rarely match each other because they use totally different methods of color reproduction and simulated gain. Also, I was under the impression that TVI was not just dot gain in that FM screening has no dot structure as with percentage screens but still has "gain", hence the term Tone Value Increase.

                              Comment

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