5 Replies Latest reply on Jun 17, 2012 8:57 AM by Gernot Hoffmann

    Is there a L*A*B to Pantone lookup table/technique

    MarieMeyer Level 1

      If I know a color's L*A*B values, is there a way I can easily located the nearest Pantone color?  I don't currently own any of the books but would buy one if there is one that provides this capability. Maybe it is just me, but I find their produce range bewildering.

        • 1. Re: Is there a L*A*B to Pantone lookup table/technique
          Gernot Hoffmann Level 3

          Marie,

           

          you can search by Photoshop.

          An example:

          Color Picker

          Type Lab 60/50/40

          Color Library

          Choose e.g. Pantone Solid Coated

          Find immediately 7416C

          Read Lab 61/49/36

           

          Or you can search here:

          http://www.fho-emden.de/~hoffmann/swatch16032005.pdf

           

          Best regards --Gernot Hoffmann

          3 people found this helpful
          • 2. Re: Is there a L*A*B to Pantone lookup table/technique
            MarieMeyer Level 1

            Thanks very much. Your document is very interesting. Are those the official Pantone LAB values, or did you measure them?  Also, I'm curious: you used D50 for the LAB values but D65 for the RGB values - why switch? I am never certain of which if these two I should use for a conversion.

            • 3. Re: Is there a L*A*B to Pantone lookup table/technique
              Gernot Hoffmann Level 3

              Marie,

               

              I don't even mention the name Pantone in my doc. With a little help

              from a friend I found a data base.

              Pantone changes the values occasionally a little. Especially there is

              some uncertainty about the CMYK represention (which is anyway

              only valid for a specific Pantoe process). In any case of doubt define

              your CMYK process in Photoshop's Color Settings, define the Spot

              color by Lab and read the equivalent CMYK values. Many Spot

              colors are out of gamut for sRGB or AdobeRGB (see my doc - if

              a number 0 or 255 for R,G,B appears, then the RGB values are

              clipped. As well, many Spots cannot be reproduced by any CMYK

              system.

              D50 is the observer illuminant and the reference for Lab for paper

              prints, a convention.

              D65 defines the reference white point for some RGB color spaces

              like sRGB and AdobeRGB, but not for all:

              http://www.fho-emden.de/~hoffmann/cielab03022003.pdf

              page 10

               

              D65 is mostly used as monitor white. Some people consider it

              as a contradiction: monitor D65 - print D50 .

              Practically it works - a matter of adaptation (one doesn't view

              the monitor and a print side by side).

               

              Best regards --Gernot Hoffmann

              1 person found this helpful
              • 4. Re: Is there a L*A*B to Pantone lookup table/technique
                MarieMeyer Level 1

                Thanks very much.  I have some several chips from the "Munsell Book of Color" and I want to reproduce their colors in an InDesign document. Do you know the software program Babelcolor CT&A? It does color conversions from many spaces to many spaces. So I could use it convert the Munsell notations to LAB. But I have to choose D50 or D65. Which would you recommend?

                • 5. Re: Is there a L*A*B to Pantone lookup table/technique
                  Gernot Hoffmann Level 3

                  Marie,

                   

                  in this doc - my Digital Munsell -

                  http://www.fho-emden.de/~hoffmann/munsell15052009.pdf

                   

                  you'll find Lab and sRGB values for Illuminant/Reference D50.

                   

                  Originally, the Munsell chips were valid under Illuminant C, which is

                  normally not available, outside of color laboratories.

                   

                  Please read the introduction - the helpful friend is mentioned as well.

                  For printig read the recommendation about the PostScript mode.

                  Printing by a non-PS printer is useless (prone to errors) - the relevant

                  data are internally defined in Lab.

                   

                  Hope this helps, we may continue tomorrow.

                   

                  Best regards --Gernot Hoffmann

                  1 person found this helpful