Graphic technology — Process control for the production of half-tone colour separations, proof and production prints — Part 8: Validation print processes working directly from digital data

ISO 12647-8:2012 specifies requirements that can be used for determining the conformance of systems that produce a hard-copy validation print, directly from digital data, which is intended to simulate the expected appearance of material printed in accordance with a characterized printing condition. ISO 12647-8:2012 is not intended for use in determining the conformance of production printing systems (digital or conventional) since many aspects of production printing are not covered.

Technologie graphique — Contrôle des processus de confection de sélections couleurs tramées, d'épreuves et de tirages — Partie 8: Processus d'impression de maquette couleur produite à partir de données numériques

Grafična tehnologija - Vodenje procesa izdelave rastriranih barvnih izvlečkov, preskusnih in proizvodnih odtisov - 8. del: Vrednotenje postopka tiskanja, izdelanega neposredno iz digitalnih podatkov

Ta del standarda ISO 12647 določa zahteve, ki jih je mogoče uporabiti pri določanju skladnosti sistemov, ki izdelajo papirno različico tiska neposredno iz digitalnih podatkov, ki je namenjena simuliranju pričakovane oblike gradiva, natisnjenega v skladu z opisanimi pogoji tiskanja. Ni namenjena določanju skladnosti sistemov proizvodnega tiskanja (digitalnih ali običajnih), saj ta del standarda ISO 12647 ne zajema številnih vidikov tiskanja.

General Information

Status
Withdrawn
Publication Date
15-Mar-2012
Withdrawal Date
15-Mar-2012
Current Stage
9599 - Withdrawal of International Standard
Start Date
31-May-2021
Completion Date
31-May-2021

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SLOVENSKI STANDARD
SIST ISO 12647-8:2014
01-november-2014
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SUHVNXVQLKLQSURL]YRGQLKRGWLVRYGHO9UHGQRWHQMHSRVWRSNDWLVNDQMD
L]GHODQHJDQHSRVUHGQRL]GLJLWDOQLKSRGDWNRY

Graphic technology - Process control for the production of half-tone colour separations,

proof and production prints - Part 8: Validation print processes working directly from

digital data

Technologie graphique - Contrôle des processus de confection de sélections couleurs

tramées, d'épreuves et de tirages - Partie 8: Processus d'impression de maquette
couleur produite à partir de données numériques
Ta slovenski standard je istoveten z: ISO 12647-8:2012
ICS:
37.100.01 *UDILþQDWHKQRORJLMDQD Graphic technology in
VSORãQR general
SIST ISO 12647-8:2014 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST ISO 12647-8:2014
---------------------- Page: 2 ----------------------
SIST ISO 12647-8:2014
INTERNATIONAL ISO
STANDARD 12647-8
First edition
2012-03-15
Graphic technology — Process control
for the production of half-tone colour
separations, proof and production
prints —
Part 8:
Validation print processes working
directly from digital data
Technologie graphique — Contrôle des processus de confection de
sélections couleurs tramées, d'épreuves et de tirages —
Partie 8: Processus d'impression de maquette couleur produite à partir
de données numériques
Reference number
ISO 12647-8:2012(E)
ISO 2012
---------------------- Page: 3 ----------------------
SIST ISO 12647-8:2014
ISO 12647-8:2012(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2012

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,

electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or

ISO's member body in the country of the requester.
ISO copyright office
Case postale 56  CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2012 – All rights reserved
---------------------- Page: 4 ----------------------
SIST ISO 12647-8:2014
ISO 12647-8:2012(E)
Contents Page

Foreword ............................................................................................................................................................ iv

Introduction ......................................................................................................................................................... v

1  Scope ...................................................................................................................................................... 1

2  Normative references ............................................................................................................................ 1

3  Terms and definitions ........................................................................................................................... 2

4  Requirements ......................................................................................................................................... 2

5  Test methods ......................................................................................................................................... 8

Annex A (informative) Determination of print durability after stabilization ................................................ 11

Annex B (normative) Surface gamut patches ................................................................................................ 14

Bibliography ...................................................................................................................................................... 16

© ISO 2012 – All rights reserved iii
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SIST ISO 12647-8:2014
ISO 12647-8:2012(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies

(ISO member bodies). The work of preparing International Standards is normally carried out through ISO

technical committees. Each member body interested in a subject for which a technical committee has been

established has the right to be represented on that committee. International organizations, governmental and

non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the

International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.

The main task of technical committees is to prepare International Standards. Draft International Standards

adopted by the technical committees are circulated to the member bodies for voting. Publication as an

International Standard requires approval by at least 75 % of the member bodies casting a vote.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent

rights. ISO shall not be held responsible for identifying any or all such patent rights.

ISO 12647-8 was prepared by Technical Committee ISO/TC 130, Graphic technology.

ISO 12647 consists of the following parts, under the general title Graphic technology — Process control for

the production of half-tone colour separations, proof and production prints:
 Part 1: Parameters and measurement methods
 Part 2: Offset lithographic processes
 Part 3: Coldset offset lithography on newsprint
 Part 4: Publication gravure printing
 Part 5: Screen printing
 Part 6: Flexographic printing
 Part 7: Proofing processes working directly from digital data
 Part 8: Validation print processes working directly from digital data
iv © ISO 2012 – All rights reserved
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SIST ISO 12647-8:2014
ISO 12647-8:2012(E)
Introduction

This part of ISO 12647 specifies the properties, and associated test methods, required for digital prints and

printing processes to meet the criteria established for “validation prints”.

In most printing workflows, there is a requirement for a visual representation of the expected appearance of

the document being printed that can be used as part of the agreement between the customer and printer.

Where this visual representation is produced such that its characteristics (colour fidelity, tone reproduction,

registration, size, etc.) simulate those of the expected printing within tight tolerances, it is usually referred to as

a “contract proof”. As the name implies, contract proofs are used as part of the contractual relationship

between customer and printer and are used as a visual aim for the press operator during printing as well as

the absolute reference against which the finished production is compared. Not unexpectedly, systems that can

produce contract proofs are usually expensive and require careful operation and maintenance. ISO 12647-7

specifies the requirements for contract proofs and systems used to produce contract proofs directly from

digital data.

Recently, other visualizations of the final printed product have found a place in the printing/proofing workflow

because designers and print buyers prefer not go to the expense of using an ISO 12647-7 compliant contract

proof any earlier in the process than necessary. In many situations, participants in the work flow require a

hardcopy visual reference of lesser quality than a contract proof. In the past, those prints varied widely in

quality and were often referred to as design proofs, concept proofs, layout prints, etc. That quality level is here

being referred to as a “validation print”.

Because data are exchanged electronically and visualizations of those data are produced at multiple sites,

there is a requirement for defined requirements for validation prints to allow a degree of consistency

throughout the workflow. One of the goals of having less stringent requirements, particularly on colour fidelity,

is to allow the production of validation prints on less elaborate and less costly devices than are required for

contract proofs. The requirements for validation prints and the systems used to produce validation prints are

documented in this part of ISO 12647.

Validation prints are not intended to replace “contract proofs” for predicting colour on production printing

devices. It is expected that the modifications of the requirements for validation prints, along with the

requirements for contract proofs, will continue in the future as industry requirements and imaging technologies

develop.
© ISO 2012 – All rights reserved v
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SIST ISO 12647-8:2014
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SIST ISO 12647-8:2014
INTERNATIONAL STANDARD ISO 12647-8:2012(E)
Graphic technology — Process control for the production of
half-tone colour separations, proof and production prints —
Part 8:
Validation print processes working directly from digital data

IMPORTANT — The electronic file of this document contains colours which are considered to be

useful for the correct understanding of the document. Users should therefore consider printing this

document using a colour printer.
1 Scope

This part of ISO 12647 specifies requirements that can be used for determining the conformance of systems

that produce a hard-copy validation print, directly from digital data, which is intended to simulate the expected

appearance of material printed in accordance with a characterized printing condition.

It is not intended for use in determining the conformance of production printing systems (digital or

conventional) since many aspects of production printing are not covered in this part of ISO 12647.

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated

references, only the edition cited applies. For undated references, the latest edition of the reference document

(including any amendments) applies.
ISO 3664:2009, Graphic technology and photography — Viewing conditions

ISO 8254-1, Paper and board — Measurement of specular gloss — Par 1: 75 degree gloss with a converging

beam, TAPPI method

ISO 12639, Graphic technology — Prepress digital data exchange — Tag image file format for image

technology (TIFF/IT)

ISO 12040, Graphic technology — Prints and printing inks — Assessment of light fastness using filtered

xenon arc light

ISO 12640-1:1997, Graphic technology — Prepress digital data exchange — Part 1: CMYK standard colour

image data (CMYK/SCID)

ISO 12642-2, Graphic technology — Input data for characterization of 4-colour process printing — Part 2:

Expanded data set

ISO 12647-1, Graphic technology — Process control for the production of half-tone colour separations, proof

and production prints — Part 1: Parameters and measurement methods

ISO 13655:2009, Graphic technology — Spectral measurement and colorimetric computation of graphic arts

images
© ISO 2012 – All rights reserved 1
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SIST ISO 12647-8:2014
ISO 12647-8:2012(E)
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 12647-1 and the following apply.

3.1
validation print substrate
printing substrate used for validation print processes

NOTE A validation print substrate is usually characterized by its light fastness or permanence properties, with only

essential requirements dictated by the printing process.
3.2
ICC
International Color Consortium
3.3
print stabilization period
time after which the colour does not change anymore

NOTE It is necessary that this property of the validation print system be specified by the manufacturer.

3.4
digital contract proof

digital print of high colour accuracy, useable as reliable visual colour reference for printing, and as a part of a

commercial agreement as defined in ISO 12647-7
3.5
validation print

print produced directly from digital data early in the production chain meeting the requirements of this part of

ISO 12647 representative of the concept for the final product
NOTE A validation print can have reduced accuracy compared to contract proof.
3.6
production print substrate
intended substrate to be used for production printing
3.7
PDF/X

title of a series of ISO standards regarding the use of the Portable Document Format (PDF) for the

dissemination of digital data intended for print reproduction
3.8
TIFF/IT
Tagged Image File Format for Image Technology
format for exchanging raster-based data in accordance with ISO 12639
4 Requirements
4.1 Data requirements for validation print systems

Validation print systems shall accept digital data delivered as PDF/X data files in accordance with ISO 15930

(all parts) or TIFF/IT files in accordance with ISO 12639. Where the digital data is delivered as PDF/X data

files, the intended printing condition being simulated shall be that defined in the OutputIntents array of the

PDF/X file. Where a profile is required for data conversion, the profile that is the value of the DestOutputProfile

key in the PDF/X file shall be used. Where TIFF/IT files are used, colour information shall be included using

tag 34675 or tag 34029.
2 © ISO 2012 – All rights reserved
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SIST ISO 12647-8:2014
ISO 12647-8:2012(E)
4.2 Validation print
4.2.1 Validation print substrate colour and gloss

The choice of the substrate used for the creation of a validation print is based on a combination of the user's

knowledge of the intended production printing substrate and the capabilities of the equipment used to create

the validation print. In cases where the production print substrate is not used for the validation print or is

unknown, then the substrate used for the validation print shall be white on both the front and the back and

shall not have any print on the back that influences the resulting measurements.

In applications where the substrate that will be used for the production print is known and the equipment used

to create the validation print is compatible with that substrate, the unmarked production print substrate shall be

used to create the validation print.

In applications where the substrate used for the production print is known, but is not compatible with the

equipment being used to create the validation print, a substrate shall be selected whose colour, measured in

accordance with ISO 13655:2009 M0 with white backing, simulates the unprinted substrate within a

CIELAB 1976 colour difference of 3.0 computed in accordance with ISO 13655. This simulation should be

determined using ISO 13655:2009 M1 with white backing, when available. This simulation of substrate colour

may be accomplished using uniform coloration of the unprinted area during creation of the validation print. In

addition, the gloss of the validation print substrate should be that of the production print substrate within

15 gloss units as measured according to 5.6. The validation print and production print substrates should

ideally have similar levels of OBA (optical brightening agents) present and exhibit the same amount of

fluorescence under an M1 illumination source.

NOTE 1 This does not imply that under other measurement conditions the simulation will be the same. The paper

industry provides methods that do not conform to ISO 13655 M0 or M1 for estimating the similarity of OBA levels but not

image colour between production print and validation print.

This part of ISO 12647 addresses situations that can occur very early in the creative process where the

intended printing production substrate is not known. In such situations, a substrate shall be selected whose

colour simulates the production substrate colour, as obtained from the characterization data set being used to

create the validation print. The tolerance on the simulation shall be a CIELAB colour difference of 3 units. The

measurement conditions targeted shall be those specified for the characterization data set being used. This

simulation of substrate colour may be accomplished using uniform coloration of the unprinted area during

creation of the validation print. In such a case, the unprinted areas of the substrate shall be removed in order

to assure adaptation to the correct white point. The gloss of the substrate shall be selected to simulate the

general type of printing expected based on the reference values of Table 1.

NOTE 2 In cases where the colour of the substrate being used to create the validation print differs from the substrate

colour in the characterization data set by more than a CIELAB colour difference of 3 and uniform coloration of the

unprinted area during creation of the validation print is not possible, the characterization data set can be adjusted to

simulate the substrate colour using the tristimulus correction technique detailed in ISO 13655. It is recommended that all

parties agree to any such change.
© ISO 2012 – All rights reserved 3
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SIST ISO 12647-8:2014
ISO 12647-8:2012(E)
Table 1 — Nominal gloss of various substrate types
Substrate type
Nominal gloss
Unit 1
Glossy white
> 60
(e.g. glossy paper
coated paper, grade 1)
Semi-matte white
(e.g. coated paper, grade 3
20 to 60
coated paper, grade 5
super-calendared paper)
Matte white
(e.g. uncoated paper,
< 20
liner board, improved newsprint,
newsprint)
Measurement according to 5.6.

Where the intended production print substrate is not used to create the validation print, the colour of the

simulated substrate, including any uniform coloration of the unprinted area, shall not vary by more than

2,5 CIELAB colour difference units when successively subjected to the following conditions in a dark

environment:
a) for 24 h at 25 °C and at a relative humidity of 25 %;
b) 24 h at 40 °C and a relative humidity of 80 %;
c) one week at 40 °C and at a relative humidity of 10 %.

In addition, its light-fastness rating as determined according to ISO 12040 shall not be less than 3.

NOTE 3 This is intended to exceed the upper level of exposure for any validation print, and any production print

substrate with significant levels of optical brightening agents is likely to fail this test. While validation prints made with the

production print substrate are exempt from this test, it is the responsibility of the user to weigh the options of simulating the

fluorescence of the validation print substrate, as noted above, to the production substrate against the requirement for

colour permanence indicated by this test.
4.2.2 Coloration of printed parts
4.2.2.1 Validation print system within sheet uniformity

The variability of the coloration across the validation print format shall be verified by printing each of the three

test forms described in 5.4. Each test form shall be measured at nine locations on each sheet as follows.

Divide the printed area into thirds both horizontally and vertically and measure at the centre of each area. All

selected locations across the printed test area for each test tint, after the stabilization period, shall have the

following:
a) standard deviation less than or equal to 1,5 for CIE L*, a* and b*;

b) maximum CIELAB colour difference of 2 units between the average of the 9 readings and any one

reading.

NOTE The requirements specified in a) and b) are not statistically consistent but have been observed to be

achievable in a well-controlled digital printing system.
4 © ISO 2012 – All rights reserved
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SIST ISO 12647-8:2014
ISO 12647-8:2012(E)
4.2.2.2 Colour simulation requirements for validation prints

The CIELAB colour coordinates of the patches of the ISO 12642-2 target and the validation print control strip

defined in 5.2 shall agree with the aim values of the printing condition being simulated as given by the data

(see 4.1) within the appropriate tolerances specified in Table 2.

NOTE 1 The colorimetric aim values for all patches are included in, or can be derived from, the colorimetric values of

the reference characterization data set.

Table 2 — Tolerances for reproduction of all patches in the validation print described in Clause 5 by

comparison to the values of the characterization data of the printing condition being simulated

Unit: 1
Patch in validation print form Tolerance
Maximum: E  8
All patches described in 5.2
Average: E  3
Patches described in 5.2 a) (C,M,Y,R,G,B) Maximum: |H |  4
Patches described in 5.2 c) Average:   2,5
Selected surface gamut patches as listed in Annex B
Average: E *  4
(taken from ISO 12642-2)
E *
Average:  3
All patches described in ISO 12642-2
95 % percentile: E  6
Due to the sign character of H, the absolute values are used.

C is the CIELAB chromaticness difference between two colours of approximately the same lightness projected onto a constant

lightness plane in the CIELAB colour space. This is calculated the same way as E , stipulated in ISO 12646.

NOTE 2 These tolerances apply only to conformance of validation printing systems. They can also be used to

determine if sites are capable of producing validation prints. They are inappropriate as tolerances for validation prints in

daily use at production sites due to the increased production costs required to maintain the equipment in this optimum

state. Experience indicates that a factor of approximately 1,5 times these tolerances is a reasonable starting point for

setting daily validation print production tolerances modified by individual user requirements.

NOTE 3 ISO/TC 130 has determined that DE2000 tolerances are now preferable to CIELAB tolerances, but exact

conversion factors are not available for this edition of this part of ISO 12647.
4.2.3 Short- and long-term repeatability

Three validation prints containing at least the primary and secondary colour solids, and primary colour mid-

tones shall be produced. There shall be a 1 h time difference between the production of the first and second

print and a one day time difference between the first and third validation print. Recalibration before production

of each print is permitted. For each print, measurements shall be made on the first print produced after the

vendor-specified warm-up period. The maximum CIELAB colour difference between any two of the three

samples of each colour shall not exceed the values shown in Table 3.
Table 3 — Repeatability of primary and secondary colour solids
and primary colour mid-tones (CIELAB 1976 colour differences)
Unit: 1
Mid-tones
Type Solids
(40 % to 50 %)
Validation print 2,5 3,0
© ISO 2012 – All rights reserved 5
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SIST ISO 12647-8:2014
ISO 12647-8:2012(E)

NOTE For certain print systems, the same point on a validation print can be formed from a different source on

different days; strictly speaking, this is testing reproducibility not repeatability. For these systems, there is no true test of

repeatability.
4.2.4 Permanence
4.2.4.1 Print stabilization period

A test should be performed and reported to verify that the print colorant has sufficient resistance to a defined

mechanical abrasion after any manufacturer's defined stabilization period. One optional test method is

specified in Annex A. In any test, the time required for the validation print solids to reach mechanical stability

shall not exceed 30 min. This test should be performed for each separate combination of materials, driving

software, colorant and printing condition that potentially can change the print stabilization time. If the validation

print has been coated, this shall be reported.
4.2.4.2 Fading and light fastness

Fading and light fastness testing shall use the solid tones of the chromatic primaries and their secondaries

C,M,Y,R,G,B plus K (7 patches). The measurement condition shall be in accordance with ISO 13655:2009 M0

with white backing, and should be as specified in ISO 13655 M1 with white backing. Colorimetric calculation

shall be in accordance with ISO 13655.

The validation print stabilization period shall be specified by the manufacturer. The variability (“fading”) of the

primary and secondary colour solids over time, in the dark, shall not exceed 2 CIELAB colour difference units

during the first 24 h after the print stabilization period.

The light fastness of the primary and secondary colour solids when tested in accordance with ISO 12040 shall

meet a light fastness rating of 3 or greater. This test shall be performed for each separate combination of

materials, driving software, colorant, printing condition and coating. The test shall begin immediately following

the validation print stabilization period specified by the manufacturer and shall be completed within weeks.

4.2.5 Ink set gloss

The gloss of solid tone colours should be identical to that of the production print to be simulated. The ink set

gloss may be specified if deemed necessary; see 5.6 for the method.

NOTE If the gloss of the final validation print is substantially different from the expected production print, a surface-

finishing step (e.g. surface laminate) to raise or lower the gloss can improve the situation.

4.2.6 Tone value reproduction limits

Tints intermediate between the (simulated) substrate white and solid shall transfer onto the validation print in a

consistent and uniform manner over a tone value range that includes at least the tone reproduction limits of

the printing condition being simulated; see the pertinent part of ISO 12647 for this information. If the target

characterization data set makes no direct reference to ISO 12647, the tone value reproduction limits shall lie

between 2 % and 98 %.

NOTE It is good practice to ensure that no significant image part is reliant on tone values outside of the tone value

reproduction limits of the expected production printing process.
4.2.7 Tonality assessment

The single-colour CMYK patches (ramps), between 30 % and 70 %, described in ISO 12642-2 should be

measured. The absolute CIE L* difference between the measured ramps and those of the reference

characterization data should be equal to or less than 2.

NOTE The usage of ∆CIE L* has a better correlation to the perceived tonality than the differences in colorimetrical

tone values.
6 © ISO 2012 – All rights reserved
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SIST ISO 12647-8:2014
ISO 12647-8:2012(E)
4.2.8 Reproduction of vignettes

Reproductions of the CMYK data in accordance with image S6 of ISO 12640-1:1997 shall show no visible

steps within the tone value reproduction limits (see 4.2.6) if viewed under ISO viewing condition P1 in

accordance with ISO 3664:2009.
4.2.9 Image resolving power

The resolving power of the validation print shall be such that C, M, K positive, sans-serif type (such as

Helvetica or Arial) of 2 point size, reverse (negative) of 8 point size and 2 point reverse line are legibly

reproduced; the test object specified in 5.3 shall be used.

NOTE This condition includes the effects of colorant migration, if at all present.

4.2.10 Margin information

4.2.10.1 Every validation print shall bear a human-readable comment that includes at least the following

information:
 conformance level (“validation print according to ISO 12647-8”);
 file name;
 validation printing system designation;
 substrate material type;
 printing condition being simulated;
 time and date of production;
 time and date of last calibration.
4.2.10.2 Every validation print should also include the following:
 colorant types;
 colour management profile(s) used;
 RIP name and version;
 scaling (if applied);
 type of coating;
 dedicated data preparation;
 type of paper/structure simulation, such as noise or patterning (if applied);

 document ID (if a PDF/X document); if a document ID is included, this shall be printed as two hex strings

and the last 6 digits of each string should be highlighted in some way in order to assist identification.

This information shall be printed on a sticker and applied to either the front or reverse side of the validation

print or shall be printed directly in a margin of the validation print.
© ISO 2012 – All rights reserved 7
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SIST ISO 12647-8:2014
ISO 12647-8:2012(E)
4.2.11 Applying conformance requirements

4.2.11.1 Validation prints produced at a validation print site shall conform to the following requirements of

this clause:

 validation print substrate colour and gloss, excluding any permanence and light fastness test; see 4.2.1;

 coloration of printed parts, except the light fastness and 24 h colour fading tests; see 4.2.2;

 tone value reproduction limits; see 4.2.6;
 tonality difference; see 4.2.7;
 reproduction of vignettes; see 4.2.8;
 image resolving power; see 4.2.9;
 margin information; see 4.2.10.

4.2.11.2 Validation print systems shall conform to the following requirements of this clause:

 validation print substrate colour and gloss; see 4.2.1;
 coloration of printed parts; see 4.2.2;
 repeatability; see 4.2.3;
 permanence; see 4.2.4;
 tone value reproduction limits; see 4.2.6;
 tonality difference; see 4.2.7;
 reproduction of vignettes; see 4.2.8;
 image resolving power; see 4.2.9.
5 T
...

INTERNATIONAL ISO
STANDARD 12647-8
First edition
2012-03-15
Graphic technology — Process control
for the production of half-tone colour
separations, proof and production
prints —
Part 8:
Validation print processes working
directly from digital data
Technologie graphique — Contrôle des processus de confection de
sélections couleurs tramées, d'épreuves et de tirages —
Partie 8: Processus d'impression de maquette couleur produite à partir
de données numériques
Reference number
ISO 12647-8:2012(E)
ISO 2012
---------------------- Page: 1 ----------------------
ISO 12647-8:2012(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2012

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,

electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or

ISO's member body in the country of the requester.
ISO copyright office
Case postale 56  CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2012 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 12647-8:2012(E)
Contents Page

Foreword ............................................................................................................................................................ iv

Introduction ......................................................................................................................................................... v

1  Scope ...................................................................................................................................................... 1

2  Normative references ............................................................................................................................ 1

3  Terms and definitions ........................................................................................................................... 2

4  Requirements ......................................................................................................................................... 2

5  Test methods ......................................................................................................................................... 8

Annex A (informative) Determination of print durability after stabilization ................................................ 11

Annex B (normative) Surface gamut patches ................................................................................................ 14

Bibliography ...................................................................................................................................................... 16

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ISO 12647-8:2012(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies

(ISO member bodies). The work of preparing International Standards is normally carried out through ISO

technical committees. Each member body interested in a subject for which a technical committee has been

established has the right to be represented on that committee. International organizations, governmental and

non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the

International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.

The main task of technical committees is to prepare International Standards. Draft International Standards

adopted by the technical committees are circulated to the member bodies for voting. Publication as an

International Standard requires approval by at least 75 % of the member bodies casting a vote.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent

rights. ISO shall not be held responsible for identifying any or all such patent rights.

ISO 12647-8 was prepared by Technical Committee ISO/TC 130, Graphic technology.

ISO 12647 consists of the following parts, under the general title Graphic technology — Process control for

the production of half-tone colour separations, proof and production prints:
 Part 1: Parameters and measurement methods
 Part 2: Offset lithographic processes
 Part 3: Coldset offset lithography on newsprint
 Part 4: Publication gravure printing
 Part 5: Screen printing
 Part 6: Flexographic printing
 Part 7: Proofing processes working directly from digital data
 Part 8: Validation print processes working directly from digital data
iv © ISO 2012 – All rights reserved
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ISO 12647-8:2012(E)
Introduction

This part of ISO 12647 specifies the properties, and associated test methods, required for digital prints and

printing processes to meet the criteria established for “validation prints”.

In most printing workflows, there is a requirement for a visual representation of the expected appearance of

the document being printed that can be used as part of the agreement between the customer and printer.

Where this visual representation is produced such that its characteristics (colour fidelity, tone reproduction,

registration, size, etc.) simulate those of the expected printing within tight tolerances, it is usually referred to as

a “contract proof”. As the name implies, contract proofs are used as part of the contractual relationship

between customer and printer and are used as a visual aim for the press operator during printing as well as

the absolute reference against which the finished production is compared. Not unexpectedly, systems that can

produce contract proofs are usually expensive and require careful operation and maintenance. ISO 12647-7

specifies the requirements for contract proofs and systems used to produce contract proofs directly from

digital data.

Recently, other visualizations of the final printed product have found a place in the printing/proofing workflow

because designers and print buyers prefer not go to the expense of using an ISO 12647-7 compliant contract

proof any earlier in the process than necessary. In many situations, participants in the work flow require a

hardcopy visual reference of lesser quality than a contract proof. In the past, those prints varied widely in

quality and were often referred to as design proofs, concept proofs, layout prints, etc. That quality level is here

being referred to as a “validation print”.

Because data are exchanged electronically and visualizations of those data are produced at multiple sites,

there is a requirement for defined requirements for validation prints to allow a degree of consistency

throughout the workflow. One of the goals of having less stringent requirements, particularly on colour fidelity,

is to allow the production of validation prints on less elaborate and less costly devices than are required for

contract proofs. The requirements for validation prints and the systems used to produce validation prints are

documented in this part of ISO 12647.

Validation prints are not intended to replace “contract proofs” for predicting colour on production printing

devices. It is expected that the modifications of the requirements for validation prints, along with the

requirements for contract proofs, will continue in the future as industry requirements and imaging technologies

develop.
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INTERNATIONAL STANDARD ISO 12647-8:2012(E)
Graphic technology — Process control for the production of
half-tone colour separations, proof and production prints —
Part 8:
Validation print processes working directly from digital data

IMPORTANT — The electronic file of this document contains colours which are considered to be

useful for the correct understanding of the document. Users should therefore consider printing this

document using a colour printer.
1 Scope

This part of ISO 12647 specifies requirements that can be used for determining the conformance of systems

that produce a hard-copy validation print, directly from digital data, which is intended to simulate the expected

appearance of material printed in accordance with a characterized printing condition.

It is not intended for use in determining the conformance of production printing systems (digital or

conventional) since many aspects of production printing are not covered in this part of ISO 12647.

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated

references, only the edition cited applies. For undated references, the latest edition of the reference document

(including any amendments) applies.
ISO 3664:2009, Graphic technology and photography — Viewing conditions

ISO 8254-1, Paper and board — Measurement of specular gloss — Par 1: 75 degree gloss with a converging

beam, TAPPI method

ISO 12639, Graphic technology — Prepress digital data exchange — Tag image file format for image

technology (TIFF/IT)

ISO 12040, Graphic technology — Prints and printing inks — Assessment of light fastness using filtered

xenon arc light

ISO 12640-1:1997, Graphic technology — Prepress digital data exchange — Part 1: CMYK standard colour

image data (CMYK/SCID)

ISO 12642-2, Graphic technology — Input data for characterization of 4-colour process printing — Part 2:

Expanded data set

ISO 12647-1, Graphic technology — Process control for the production of half-tone colour separations, proof

and production prints — Part 1: Parameters and measurement methods

ISO 13655:2009, Graphic technology — Spectral measurement and colorimetric computation of graphic arts

images
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ISO 12647-8:2012(E)
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 12647-1 and the following apply.

3.1
validation print substrate
printing substrate used for validation print processes

NOTE A validation print substrate is usually characterized by its light fastness or permanence properties, with only

essential requirements dictated by the printing process.
3.2
ICC
International Color Consortium
3.3
print stabilization period
time after which the colour does not change anymore

NOTE It is necessary that this property of the validation print system be specified by the manufacturer.

3.4
digital contract proof

digital print of high colour accuracy, useable as reliable visual colour reference for printing, and as a part of a

commercial agreement as defined in ISO 12647-7
3.5
validation print

print produced directly from digital data early in the production chain meeting the requirements of this part of

ISO 12647 representative of the concept for the final product
NOTE A validation print can have reduced accuracy compared to contract proof.
3.6
production print substrate
intended substrate to be used for production printing
3.7
PDF/X

title of a series of ISO standards regarding the use of the Portable Document Format (PDF) for the

dissemination of digital data intended for print reproduction
3.8
TIFF/IT
Tagged Image File Format for Image Technology
format for exchanging raster-based data in accordance with ISO 12639
4 Requirements
4.1 Data requirements for validation print systems

Validation print systems shall accept digital data delivered as PDF/X data files in accordance with ISO 15930

(all parts) or TIFF/IT files in accordance with ISO 12639. Where the digital data is delivered as PDF/X data

files, the intended printing condition being simulated shall be that defined in the OutputIntents array of the

PDF/X file. Where a profile is required for data conversion, the profile that is the value of the DestOutputProfile

key in the PDF/X file shall be used. Where TIFF/IT files are used, colour information shall be included using

tag 34675 or tag 34029.
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ISO 12647-8:2012(E)
4.2 Validation print
4.2.1 Validation print substrate colour and gloss

The choice of the substrate used for the creation of a validation print is based on a combination of the user's

knowledge of the intended production printing substrate and the capabilities of the equipment used to create

the validation print. In cases where the production print substrate is not used for the validation print or is

unknown, then the substrate used for the validation print shall be white on both the front and the back and

shall not have any print on the back that influences the resulting measurements.

In applications where the substrate that will be used for the production print is known and the equipment used

to create the validation print is compatible with that substrate, the unmarked production print substrate shall be

used to create the validation print.

In applications where the substrate used for the production print is known, but is not compatible with the

equipment being used to create the validation print, a substrate shall be selected whose colour, measured in

accordance with ISO 13655:2009 M0 with white backing, simulates the unprinted substrate within a

CIELAB 1976 colour difference of 3.0 computed in accordance with ISO 13655. This simulation should be

determined using ISO 13655:2009 M1 with white backing, when available. This simulation of substrate colour

may be accomplished using uniform coloration of the unprinted area during creation of the validation print. In

addition, the gloss of the validation print substrate should be that of the production print substrate within

15 gloss units as measured according to 5.6. The validation print and production print substrates should

ideally have similar levels of OBA (optical brightening agents) present and exhibit the same amount of

fluorescence under an M1 illumination source.

NOTE 1 This does not imply that under other measurement conditions the simulation will be the same. The paper

industry provides methods that do not conform to ISO 13655 M0 or M1 for estimating the similarity of OBA levels but not

image colour between production print and validation print.

This part of ISO 12647 addresses situations that can occur very early in the creative process where the

intended printing production substrate is not known. In such situations, a substrate shall be selected whose

colour simulates the production substrate colour, as obtained from the characterization data set being used to

create the validation print. The tolerance on the simulation shall be a CIELAB colour difference of 3 units. The

measurement conditions targeted shall be those specified for the characterization data set being used. This

simulation of substrate colour may be accomplished using uniform coloration of the unprinted area during

creation of the validation print. In such a case, the unprinted areas of the substrate shall be removed in order

to assure adaptation to the correct white point. The gloss of the substrate shall be selected to simulate the

general type of printing expected based on the reference values of Table 1.

NOTE 2 In cases where the colour of the substrate being used to create the validation print differs from the substrate

colour in the characterization data set by more than a CIELAB colour difference of 3 and uniform coloration of the

unprinted area during creation of the validation print is not possible, the characterization data set can be adjusted to

simulate the substrate colour using the tristimulus correction technique detailed in ISO 13655. It is recommended that all

parties agree to any such change.
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ISO 12647-8:2012(E)
Table 1 — Nominal gloss of various substrate types
Substrate type
Nominal gloss
Unit 1
Glossy white
> 60
(e.g. glossy paper
coated paper, grade 1)
Semi-matte white
(e.g. coated paper, grade 3
20 to 60
coated paper, grade 5
super-calendared paper)
Matte white
(e.g. uncoated paper,
< 20
liner board, improved newsprint,
newsprint)
Measurement according to 5.6.

Where the intended production print substrate is not used to create the validation print, the colour of the

simulated substrate, including any uniform coloration of the unprinted area, shall not vary by more than

2,5 CIELAB colour difference units when successively subjected to the following conditions in a dark

environment:
a) for 24 h at 25 °C and at a relative humidity of 25 %;
b) 24 h at 40 °C and a relative humidity of 80 %;
c) one week at 40 °C and at a relative humidity of 10 %.

In addition, its light-fastness rating as determined according to ISO 12040 shall not be less than 3.

NOTE 3 This is intended to exceed the upper level of exposure for any validation print, and any production print

substrate with significant levels of optical brightening agents is likely to fail this test. While validation prints made with the

production print substrate are exempt from this test, it is the responsibility of the user to weigh the options of simulating the

fluorescence of the validation print substrate, as noted above, to the production substrate against the requirement for

colour permanence indicated by this test.
4.2.2 Coloration of printed parts
4.2.2.1 Validation print system within sheet uniformity

The variability of the coloration across the validation print format shall be verified by printing each of the three

test forms described in 5.4. Each test form shall be measured at nine locations on each sheet as follows.

Divide the printed area into thirds both horizontally and vertically and measure at the centre of each area. All

selected locations across the printed test area for each test tint, after the stabilization period, shall have the

following:
a) standard deviation less than or equal to 1,5 for CIE L*, a* and b*;

b) maximum CIELAB colour difference of 2 units between the average of the 9 readings and any one

reading.

NOTE The requirements specified in a) and b) are not statistically consistent but have been observed to be

achievable in a well-controlled digital printing system.
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ISO 12647-8:2012(E)
4.2.2.2 Colour simulation requirements for validation prints

The CIELAB colour coordinates of the patches of the ISO 12642-2 target and the validation print control strip

defined in 5.2 shall agree with the aim values of the printing condition being simulated as given by the data

(see 4.1) within the appropriate tolerances specified in Table 2.

NOTE 1 The colorimetric aim values for all patches are included in, or can be derived from, the colorimetric values of

the reference characterization data set.

Table 2 — Tolerances for reproduction of all patches in the validation print described in Clause 5 by

comparison to the values of the characterization data of the printing condition being simulated

Unit: 1
Patch in validation print form Tolerance
Maximum: E  8
All patches described in 5.2
Average: E  3
Patches described in 5.2 a) (C,M,Y,R,G,B) Maximum: |H |  4
Patches described in 5.2 c) Average:   2,5
Selected surface gamut patches as listed in Annex B
Average: E *  4
(taken from ISO 12642-2)
E *
Average:  3
All patches described in ISO 12642-2
95 % percentile: E  6
Due to the sign character of H, the absolute values are used.

C is the CIELAB chromaticness difference between two colours of approximately the same lightness projected onto a constant

lightness plane in the CIELAB colour space. This is calculated the same way as E , stipulated in ISO 12646.

NOTE 2 These tolerances apply only to conformance of validation printing systems. They can also be used to

determine if sites are capable of producing validation prints. They are inappropriate as tolerances for validation prints in

daily use at production sites due to the increased production costs required to maintain the equipment in this optimum

state. Experience indicates that a factor of approximately 1,5 times these tolerances is a reasonable starting point for

setting daily validation print production tolerances modified by individual user requirements.

NOTE 3 ISO/TC 130 has determined that DE2000 tolerances are now preferable to CIELAB tolerances, but exact

conversion factors are not available for this edition of this part of ISO 12647.
4.2.3 Short- and long-term repeatability

Three validation prints containing at least the primary and secondary colour solids, and primary colour mid-

tones shall be produced. There shall be a 1 h time difference between the production of the first and second

print and a one day time difference between the first and third validation print. Recalibration before production

of each print is permitted. For each print, measurements shall be made on the first print produced after the

vendor-specified warm-up period. The maximum CIELAB colour difference between any two of the three

samples of each colour shall not exceed the values shown in Table 3.
Table 3 — Repeatability of primary and secondary colour solids
and primary colour mid-tones (CIELAB 1976 colour differences)
Unit: 1
Mid-tones
Type Solids
(40 % to 50 %)
Validation print 2,5 3,0
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ISO 12647-8:2012(E)

NOTE For certain print systems, the same point on a validation print can be formed from a different source on

different days; strictly speaking, this is testing reproducibility not repeatability. For these systems, there is no true test of

repeatability.
4.2.4 Permanence
4.2.4.1 Print stabilization period

A test should be performed and reported to verify that the print colorant has sufficient resistance to a defined

mechanical abrasion after any manufacturer's defined stabilization period. One optional test method is

specified in Annex A. In any test, the time required for the validation print solids to reach mechanical stability

shall not exceed 30 min. This test should be performed for each separate combination of materials, driving

software, colorant and printing condition that potentially can change the print stabilization time. If the validation

print has been coated, this shall be reported.
4.2.4.2 Fading and light fastness

Fading and light fastness testing shall use the solid tones of the chromatic primaries and their secondaries

C,M,Y,R,G,B plus K (7 patches). The measurement condition shall be in accordance with ISO 13655:2009 M0

with white backing, and should be as specified in ISO 13655 M1 with white backing. Colorimetric calculation

shall be in accordance with ISO 13655.

The validation print stabilization period shall be specified by the manufacturer. The variability (“fading”) of the

primary and secondary colour solids over time, in the dark, shall not exceed 2 CIELAB colour difference units

during the first 24 h after the print stabilization period.

The light fastness of the primary and secondary colour solids when tested in accordance with ISO 12040 shall

meet a light fastness rating of 3 or greater. This test shall be performed for each separate combination of

materials, driving software, colorant, printing condition and coating. The test shall begin immediately following

the validation print stabilization period specified by the manufacturer and shall be completed within weeks.

4.2.5 Ink set gloss

The gloss of solid tone colours should be identical to that of the production print to be simulated. The ink set

gloss may be specified if deemed necessary; see 5.6 for the method.

NOTE If the gloss of the final validation print is substantially different from the expected production print, a surface-

finishing step (e.g. surface laminate) to raise or lower the gloss can improve the situation.

4.2.6 Tone value reproduction limits

Tints intermediate between the (simulated) substrate white and solid shall transfer onto the validation print in a

consistent and uniform manner over a tone value range that includes at least the tone reproduction limits of

the printing condition being simulated; see the pertinent part of ISO 12647 for this information. If the target

characterization data set makes no direct reference to ISO 12647, the tone value reproduction limits shall lie

between 2 % and 98 %.

NOTE It is good practice to ensure that no significant image part is reliant on tone values outside of the tone value

reproduction limits of the expected production printing process.
4.2.7 Tonality assessment

The single-colour CMYK patches (ramps), between 30 % and 70 %, described in ISO 12642-2 should be

measured. The absolute CIE L* difference between the measured ramps and those of the reference

characterization data should be equal to or less than 2.

NOTE The usage of ∆CIE L* has a better correlation to the perceived tonality than the differences in colorimetrical

tone values.
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ISO 12647-8:2012(E)
4.2.8 Reproduction of vignettes

Reproductions of the CMYK data in accordance with image S6 of ISO 12640-1:1997 shall show no visible

steps within the tone value reproduction limits (see 4.2.6) if viewed under ISO viewing condition P1 in

accordance with ISO 3664:2009.
4.2.9 Image resolving power

The resolving power of the validation print shall be such that C, M, K positive, sans-serif type (such as

Helvetica or Arial) of 2 point size, reverse (negative) of 8 point size and 2 point reverse line are legibly

reproduced; the test object specified in 5.3 shall be used.

NOTE This condition includes the effects of colorant migration, if at all present.

4.2.10 Margin information

4.2.10.1 Every validation print shall bear a human-readable comment that includes at least the following

information:
 conformance level (“validation print according to ISO 12647-8”);
 file name;
 validation printing system designation;
 substrate material type;
 printing condition being simulated;
 time and date of production;
 time and date of last calibration.
4.2.10.2 Every validation print should also include the following:
 colorant types;
 colour management profile(s) used;
 RIP name and version;
 scaling (if applied);
 type of coating;
 dedicated data preparation;
 type of paper/structure simulation, such as noise or patterning (if applied);

 document ID (if a PDF/X document); if a document ID is included, this shall be printed as two hex strings

and the last 6 digits of each string should be highlighted in some way in order to assist identification.

This information shall be printed on a sticker and applied to either the front or reverse side of the validation

print or shall be printed directly in a margin of the validation print.
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ISO 12647-8:2012(E)
4.2.11 Applying conformance requirements

4.2.11.1 Validation prints produced at a validation print site shall conform to the following requirements of

this clause:

 validation print substrate colour and gloss, excluding any permanence and light fastness test; see 4.2.1;

 coloration of printed parts, except the light fastness and 24 h colour fading tests; see 4.2.2;

 tone value reproduction limits; see 4.2.6;
 tonality difference; see 4.2.7;
 reproduction of vignettes; see 4.2.8;
 image resolving power; see 4.2.9;
 margin information; see 4.2.10.

4.2.11.2 Validation print systems shall conform to the following requirements of this clause:

 validation print substrate colour and gloss; see 4.2.1;
 coloration of printed parts; see 4.2.2;
 repeatability; see 4.2.3;
 permanence; see 4.2.4;
 tone value reproduction limits; see 4.2.6;
 tonality difference; see 4.2.7;
 reproduction of vignettes; see 4.2.8;
 image resolving power; see 4.2.9.
5 Test methods
5.1 System validation

The system being tested shall first digitally print a test form minimally consisting of the control strip described in

5.2 and all the patches in accordance with ISO 12642-2. Printing shall be targeted at a specific printing

condition with a known characterization data set (see 4.1).
5.2 Validation print control strip

The control elements of the CMYK control strip, as identified in the list below, shall be included while keeping

the total number of patches within reasonable limits. To provide compatibility with characterization data, as

many control patches as possible should be selected from ink value combinations of ISO 12642-2. The control

patch types being used are a selection of critical tertiary colours, such as flesh tones, brown, aubergine, violet

(e.g. 15 patches).

A CMYK digital control strip shall be printed on every validation print. That control strip shall consist of at least

the following patches:

a) solid tones of the chromatic primaries, their secondaries and black C,M,Y,R,G,B,K (7 patches);

b) mid-tones of the chromatic primaries and black C,M,Y,K;
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ISO 12647-8:2012(E)

c) a minimum 5-step near-neutral tone scale composed of the primaries C, M, Y which is approximately

equally spaced in CIE L* from substrate (or simulated substrate) to the 3-colour minimum L* and shall

have a chroma le
...

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