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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.
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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
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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.
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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
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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?
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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
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Hi Marie
Pantone is all about putting an extra "special" or "spot" colour on a printing press. The spot ink is normally mixed from special base inks using expertise, tables and a weighing scale
Pantone 'CMYK process equivalents' seem to be based on mystery CMYK, not ideal IMO.
If your print process is CMYK (process inks only, no extra colour on the press) then you need to know what CMYK profile is being used to successfully convert RGB images for that publication.
Then use Photoshop to convert Lab to CMYK (with Absolute Colorimetric Rendering)
You can measure swatches in Lab using a spectrophotometer, useful tool if doing this a lot.
I hope this helps
if so, please "like" my reply
thanks
neil barstow, colourmanagement.net
[please do not use the reply button on a message in the thread, only use the one at the top of the page, to maintain chronological order]
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Gernot
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
that’s interesting
please describe the actual steps between step 2 and 3
1 Color Picker
2 Type Lab 60/50/40
- - - ?
3 Color Library
4 Choose e.g. Pantone Solid Coated
thanks
neil barstow