Greetings,

We are working with an artist that is asking that we convert his PMS (Spot) colors to process mixes based on SWOP values. He also indicates that his proof, while being printed on a non-postscript printer, is color accurate to SWOP - YEAH!

We are a flexo printer and prefer to print PMS colors as opposed to CMYK equivalents, however we are willing to work with a customer. In an attempt to find out what SWOP values are I tried the following:

Checked the values listed in the Gracol 2007 spec, which for 310 TAC 150% #3 are:

C= 57.06, -36.97, -45.05

M= 47.99, 71.92, -3.10

Y= 88.08, -5.09, 87.90

K= 18.97, 1.10, 1.18

Created a file in Photoshop whose working space is U.S. Web Coated (SWOP) v2 (8bpc) and the values are:

C= 62, -44, -50

M= 52, 81, -7

Y= 95, -6, 95

K= 12, 2, 0

The artist proof values are:

C= 56.20, -32.69, -47.19

M= 48.92, 65.57, -9.56

Y= 85.23, -5.54, 73.44

K= 15.44, 0.41, -0.56

I am guessing this artist does not have a spectro because his "color accurate proof" is, CMYK respectively, off by dEs of, 5.62,5.33, 7.28, and 4.14.

If we accept this order I am sure I will need to discuss color with the artist and I would like to know what are the correct Lab values for SWOP solid CMYK.

While checking out values I decided to convert the solid CMYK U.S. Web Coated (SWOP) v2 (8bpc) file to Gracol2006_Coated1v2.icc and check some numbers. They do not appear to match the numbers listed for Lab values in the G7 How To Guide, nor the GracolSpec2007. Additionally, if I start from scratch and create a file using the Gracol2006_Coated1v2.icc profile as a working space its CMYK Lab values do not match the numbers I get when I converted from CMYK U.S. Web Coated (SWOP) v2 (8bpc) to Gracol2006_Coated1v2.icc.

Numbers, I am confused!! I thought the Gracol2006_Coated1v2.icc was based on the '06 Gracol G7 work - am I wrong? When one converts solids from one color space I would expect them to be the same Lab values as if I had started in the conversion workspace - am I wrong?

Are the SWOP Lab values for solid CMYK values using CMYK U.S. Web Coated (SWOP) v2 (8bpc) as a working space the "real" values for SWOP? If so how do they relate to the GracolSpec2007 SWOP values?

Thanks in advance to all that answer.

"your favorite flexo printer"

-Bill-

We are working with an artist that is asking that we convert his PMS (Spot) colors to process mixes based on SWOP values. He also indicates that his proof, while being printed on a non-postscript printer, is color accurate to SWOP - YEAH!

We are a flexo printer and prefer to print PMS colors as opposed to CMYK equivalents, however we are willing to work with a customer. In an attempt to find out what SWOP values are I tried the following:

Checked the values listed in the Gracol 2007 spec, which for 310 TAC 150% #3 are:

C= 57.06, -36.97, -45.05

M= 47.99, 71.92, -3.10

Y= 88.08, -5.09, 87.90

K= 18.97, 1.10, 1.18

Created a file in Photoshop whose working space is U.S. Web Coated (SWOP) v2 (8bpc) and the values are:

C= 62, -44, -50

M= 52, 81, -7

Y= 95, -6, 95

K= 12, 2, 0

The artist proof values are:

C= 56.20, -32.69, -47.19

M= 48.92, 65.57, -9.56

Y= 85.23, -5.54, 73.44

K= 15.44, 0.41, -0.56

I am guessing this artist does not have a spectro because his "color accurate proof" is, CMYK respectively, off by dEs of, 5.62,5.33, 7.28, and 4.14.

If we accept this order I am sure I will need to discuss color with the artist and I would like to know what are the correct Lab values for SWOP solid CMYK.

While checking out values I decided to convert the solid CMYK U.S. Web Coated (SWOP) v2 (8bpc) file to Gracol2006_Coated1v2.icc and check some numbers. They do not appear to match the numbers listed for Lab values in the G7 How To Guide, nor the GracolSpec2007. Additionally, if I start from scratch and create a file using the Gracol2006_Coated1v2.icc profile as a working space its CMYK Lab values do not match the numbers I get when I converted from CMYK U.S. Web Coated (SWOP) v2 (8bpc) to Gracol2006_Coated1v2.icc.

Numbers, I am confused!! I thought the Gracol2006_Coated1v2.icc was based on the '06 Gracol G7 work - am I wrong? When one converts solids from one color space I would expect them to be the same Lab values as if I had started in the conversion workspace - am I wrong?

Are the SWOP Lab values for solid CMYK values using CMYK U.S. Web Coated (SWOP) v2 (8bpc) as a working space the "real" values for SWOP? If so how do they relate to the GracolSpec2007 SWOP values?

Thanks in advance to all that answer.

"your favorite flexo printer"

-Bill-

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