World Association of Newspapers and News Publishers


Self Check updated. What are the changes?

Self Check updated. What are the changes?

Article ID:

18318

The change made on 12 January 2016 is in the section, “Color register”. Please refer section VI of this article. ISO 12647-3, the quality standard for coldset offset newspaper production, has been revised recently. Some of the revised recommendations have been incorporated in the WAN-IFRA Self check. These changes are applicable to INCQC 2016-18 as well.

Self Check is available only for category 1, 2 and 3. However, this article also covers the changes for Category 4.

A new WAN-IFRA Cuboid can be downloaded from the bottom of this webpage and is also available in the download section of the website www.colorqualityclub.org. The evaluation based on the old WAN-IFRA Cuboid will be available along-side the new evaluation untill end of November 2014.

 

 I. WAN-IFRA cuboid

Patch D6 is changed from a 240% Total Area Coverage (TAC) 4-Color black to 220% TAC 4-Color black. The revised values are C 44%; M 38%; Y 38%; K 100%.

Patch D5, which was earlier 3-Color max gray, is now replaced by 4-Color Black with 240% TAC. The values of the patch are C 52%; M 44%; Y 44%; K 100%.

The revised ISO 12647-3 standard recommends a TAC of 220 for cold-set newspaper production. However, 220 TAC is too low for other categories. Therefore, the new cuboid contains both 240 TAC and 220 TAC.

Patch D6 (220 TAC) should be considered for all 4-Color Black measurement for category 1. Patch D5 (240 TAC) should be considered for all 4-Color Black measurement for category 2, 3 & 4.

 

II. Dot gain

For Category 1, the target dot gain at 40% patch is changed from 26.1 to 26.2, in-line with the latest revision of ISO 12647-3. There is no change for other categories.

 

III. Gray balance

To calculate the targets for light, medium and dark gray, the L*a*b* values of paper white and the 4-Color Black are used.

For category 1, the L*a*b* values of 4-Color black are measured from patch D6.

For category 2, 3 & 4, the L*a*b* values of 4-Color black are measured from patch D5.

 

IV. Color gamut

The color gamut is calculated from the L*a*b* values of solid Cyan, Magenta, Yellow, Red, Green, Blue and 4-Color Black.

For category 1, the target L*a*b* values of Magenta are revised to L* 54; a* 44; b* -1.

For Category 1, the L*a*b* values of 4-Color black are measured from patch D6.

For category 2 & 3, the L*a*b* values of 4-Color black are measured from patch D5.

Category 4 does not have this section

 

V. Color conformity of individual colors

For category 1, the target L*a*b* values of Magenta are revised to L* 54; a* 44; b* -1.

For category 4, the L*a*b* value of 4-Color Black are measured from patch D5

 

VI. Color register

For all the three categories, the tolerance for register deviation is modified, in-line with the latest ISO revision. The maximum register deviation tolerance is reduced from 300 microns to 200 microns.

For a register deviation of 200 microns or less, 30 points are awarded. For a deviation above 200 microns, no points are awarded.


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Author

Anandaramakrishnan Srinivasan's picture

Anandaramakrishnan Srinivasan

Date

2014-11-11 13:29

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The International Newspaper Color Quality Club is the only worldwide printing quality competition for newspapers. Its goal is to improve the quality of reproduction and printing in production, while also increasing competitiveness as well as training and motivating all personnel. Read more ...