Graphic technology — Process control for the production of half-tone colour separations, proof and production prints — Part 7: Proofing processes working directly from digital data

ISO 12647-7:2013 specifies requirements for systems that are used to produce hard-copy digital proof prints intended to simulate a printing condition defined by a set of characterization data. Recommendations are provided with regard to appropriate test methods associated with these requirements. ISO 12647-7:2013 is independent of the method used to produce a digital proof print.

Technologie graphique — Contrôle des processus de confection de sélections couleurs tramées, d'épreuves et de tirages — Partie 7: Processus d'épreuve travaillant directement à partir de données numériques

Grafična tehnologija - Vodenje procesa izdelave rastriranih barvnih izvlečkov, preskusnih in proizvodnih odtisov - 7. del: Neposredni preskusni procesi z digitalnimi podatki

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Withdrawn
Publication Date
18-Jul-2013
Withdrawal Date
18-Jul-2013
Current Stage
9599 - Withdrawal of International Standard
Start Date
04-Nov-2016
Completion Date
04-Nov-2016

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INTERNATIONAL ISO
STANDARD 12647-7
Second edition
2013-07-01
Graphic technology — Process
control for the production of half-
tone colour separations, proof and
production prints —
Part 7:
Proofing processes working directly
from digital data
Technologie graphique — Contrôle des processus de confection de
sélections couleurs tramées, d’épreuves et de tirages —
Partie 7: Processus d’épreuve travaillant directement à partir de
données numériques
Reference number
ISO 12647-7:2013(E)
ISO 2013
---------------------- Page: 1 ----------------------
ISO 12647-7:2013(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2013

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

or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior

written permission. Permission can be requested 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 2013 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 12647-7:2013(E)
Contents Page

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

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

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

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

3 Terms and definitions ..................................................................................................................................................................................... 1

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

4.1 Data files, simulation of screens............................................................................................................................................... 2

4.2 Proof print ................................................................................................................................................................................................... 3

5 Test methods ............................................................................................................................................................................................................. 6

5.1 Control strip .............................................................................................................................................................................................. 6

5.2 Additional test objects ...................................................................................................................................................................... 7

5.3 Colour measurement ......................................................................................................................................................................... 7

5.4 Measurement of tone values by tristimulus colourimeter or spectrocolourimeter ................... 8

5.5 Measurement of gloss ....................................................................................................................................................................... 8

5.6 Visual appraisal of proof-press-print matches ............................................................................................................ 8

Annex A (normative) Certification .......................................................................................................................................................................... 9

Annex B (normative) Rub resistance of the proof colourant ...................................................................................................11

Annex C (normative) Outer gamut patches.................................................................................................................................................14

Annex D (informative) Organisational certification routines for visual appraisal of proof-print

press-print matches .......................................................................................................................................................................................20

Bibliography .............................................................................................................................................................................................................................22

© ISO 2013 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 12647-7:2013(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.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directives

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. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received. www.iso.org/patents

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.
The committee responsible for this document is ISO/TC 130, Graphic technology.

This second edition cancels and replaces the first edition (ISO 12647-7:2007), of which it constitutes a

minor revision with the following changes:

— clear up the subject matter on certification issues to comply with the ISO requirements;

— update of references.

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 2013 – All rights reserved
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ISO 12647-7:2013(E)
Introduction

ISO 12647-1 serves to provide definitions, the general principles, the general order, the material to be

covered in ISO 12647-2 to ISO 12647-7, the definition of the data, the measurement conditions, and the

reporting style.

This part of ISO 12647 relates to the subject of digital proofing and establishes proofing requirements

for the most stringent part of the printing and publishing market.

This part of ISO 12647 mainly lists values or sets of values, and their tolerances, of the primary parameters

specified in ISO 12647-1, especially for digital proof printing. Primary parameters that define a printing

condition include the screening parameters, where applicable, the colours of the solids, the colour of the

print substrate, colours intermediate between these and the tone value increase curve. Adherence to

these values essentially ensures that a grey, which at the colour separation stage was composed for a

particular printing condition, also prints as a grey colour in proofing and printing. Remaining deviations

from grey due to differences in trapping can then be removed by adjusting the colouration within the

tolerances provided. This part of ISO 12647 further specifies test methods for those properties of digital

proof prints and their substrates that are considered relevant for stable and reliable conditions, and

thus for a certification procedure.

The graphic technology industry makes extensive use of proofing to predict the rendering of digital

data files by a wide variety of high-definition, high-quality off-press printing processes and applications.

Each prediction is based on a characterisation data set that defines a particular printing condition.

Typically, the specified printing condition is defined through an International Color Consortium (ICC)

profile or the associated characterisation data set, both of which relate source data and colourimetrically

defined printed colour. Such data may be derived from printing conditions conforming to the pertinent

process standard of the ISO 12647 series by industry trade groups or individuals.

The purpose of a proof print is to simulate the visual characteristics of the finished production print

product as closely as possible. In order to visually match a particular printing condition, proofing

processes require a set of parameters to be specified that are not necessarily identical to those put

forward in ISO 12647-1 or another part of ISO 12647. This is caused by differences in colourant spectra

or phenomena such as gloss, light scatter (within the print substrate or the colourant), and transparency.

In such cases, it is also found that spectrocolourimetry takes precedence over densitometry.

Another problem area is the matching of a double-sided production print on a lightweight printing substrate,

such as often used in heat-set web and publication gravure printing, to a digital proof on a nearly opaque

substrate. If the proof was produced using a colour management profile based on measurements with white

backing, there will be an unavoidable visual and measurable difference between the proof on the one hand

and the production print placed on black on the other hand. A black backing is required for double-sided

production printing on non-opaque prints, as specified in the pertinent parts of ISO 12647. The possible

occurrence of such differences needs to be well communicated, in advance, to all parties concerned.

Historically, there has been no consistency in the way that either the characterisation data or the criteria

and limits for a satisfactory match have been provided. This has led to significant redundancy and

inconsistencies in the evaluation of proofing systems for different, but similar, applications, and a cost

and time burden on the industry. This International Standard therefore attempts to provide guidance in

this area by providing specifications and associated testing procedures.

Annex A gives the requirements for the digital proof prints listed in the main body of this part of

ISO 12647; these are weighted with respect to their relevance in two typical situations:

— requirements with which a proof print, made for a particular printing condition, must comply if it

is to be referenced in a contract between the printer and the provider of the digital data (“Certified

Proofing System”);

— requirements with which a vendor’s proofing system, comprising hardware and software, must

comply if it is to be considered capable of reliably producing digital contract proofs for a particular

printing condition (“Certified Proofing System”).
© ISO 2013 – All rights reserved v
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INTERNATIONAL STANDARD ISO 12647-7:2013(E)
Graphic technology — Process control for the production of
half-tone colour separations, proof and production prints —
Part 7:
Proofing processes working directly from digital data
1 Scope

This part of ISO 12647 specifies requirements for systems that are used to produce hard-copy

digital proof prints intended to simulate a printing condition defined by a set of characterisation

data. Recommendations are provided with regard to appropriate test methods associated with these

requirements.

This part of ISO 12647 is independent of the method used to produce a digital proof print.

2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are

indispensable for its application. For dated references, only the edition cited applies. For undated

references, the latest edition of the referenced document (including any amendments) applies.

ISO 3664, Graphic technology and photography — Viewing conditions

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

beam, TAPPI method

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

xenon arc light

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

technology (TIFF/IT)

ISO 12640-1, 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 12647-1:2004, Graphic technology — Process control for the production of half-tone colour separations,

proof and production prints — Part 1: Parameters and measurement methods

ISO 13655, Graphic technology — Spectral measurement and colorimetric computation for graphic arts images

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
digital proof

soft proof or hard-copy proof produced directly from digital data, on a display or a substrate

© ISO 2013 – All rights reserved 1
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ISO 12647-7:2013(E)
3.2
digital proof print
digital hard-copy proof
digital proof produced as a reflection copy on a proofing substrate
3.3
proofing substrate
printing substrate used for hard-copy proofing processes
3.4
half-tone proof print

proof print made using the same screening technology (generally centre-weighted half-tone dots) as the

intended production printing

Note 1 to entry: This is done to attempt to produce (and therefore check for the existence of) the same screening

artefacts, such as rosettes, moiré, or aliasing patterns, as expected in the corresponding production print. One

possibility is to base proofing on the bitmap produced on the production plate or film setter.

3.5
print stabilisation period

time elapsed since the production of a proof print until a stable colour is achieved

Note 1 to entry: This property is to be specified by the manufacturer.
4 Requirements
4.1 Data files, simulation of screens
4.1.1 Data delivery

Digital proofing systems should accept digital data delivered as PDF/X data files as defined in ISO 15930

(all parts) or TIFF/IT files as defined in ISO 12639. Where TIFF/IT files are used, colour information

shall be included using tag 34675 or tag 34029 as defined in ISO 12639.

NOTE PDF/X requires that the intended printing condition be indicated. Where the intended printing

condition is included in the registry of characterisations maintained by the International Color Consortium (ICC)

and the digital data are cyan-magenta-yellow-key (black) (CMYK), the name used in the ICC registry is usually

used for identification in lieu of including an ICC output profile. If the intended printing condition is not included

in said registry, PDF/X requires that an ICC output profile be included. If the data are other than CMYK, the data

are required to be defined colourimetrically using an ICC input profile or another mechanism and an ICC CMYK

output profile is required to be included; the rendering intent to be used with the output profile is required to be

communicated.
4.1.2 Screen frequency

Half-tone proofs should have the same nominal screen frequencies (screen rulings) as the production

press print to be simulated.
4.1.3 Screen angle

Half-tone proofs should have the same screen angles as the production print to be simulated.

4.1.4 Dot shape and its relationship to tone value

Half-tone proofs should have the same general dot shape as the production print to be simulated.

2 © ISO 2013 – All rights reserved
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ISO 12647-7:2013(E)
4.2 Proof print
4.2.1 Proofing substrate colour and gloss

The digital proofing substrate should, if possible, be the same as the substrate to be used for production

printing. Where this is not possible, the digital proofing substrate should have the same gloss and CIELAB

a* and b* values as the intended production printing substrate within the tolerances listed in Table 1.

Where the characteristics of the printing substrate to be used for production printing are not exactly

known, a suitable proofing substrate conforming to one of the three types given in Table 1 shall be used.

The proof and production printing substrates should ideally have similar UV responses under the

recommended measurement conditions.

Annex A gives requirements for a digital proof print that are weighted with respect to their relevance.

Where the production printing substrate is not identical to the proofing substrate, the colour of the

latter shall not vary by more than a CIELAB 1976 colour difference of 1,5 when successively subjected to

the following storage conditions in the dark:
a) 24 h at 25 °C and a relative humidity of 25 %;
b) 24 h at 40 °C and a relative humidity of 80 %;
c) one week at 40 °C and a relative humidity of 10 %.

For the same proofing substrate, the variability of colour under light exposure is limited by the condition

that the light fastness, as determined in accordance with ISO 12040, shall not be less than 3.

NOTE 1 A light fastness step of 3 corresponds approximately to a 300 d exposure to normal office lighting.

NOTE 2 In production printing, if the final print product is subjected to surface finishing, this might significantly

affect the gloss and often also the colour. In critical cases, the result of the colour separation stage is best judged

by means of a proof that closely matches the gloss of the final surface-finished print product. For processes with

off-press finishing, in order to facilitate the matching of the production image to the proof image at the make-

ready stage, it is useful to provide the press operator with two proof prints:

— a proof print whose gloss matches that of the (unfinished) production print substrate;

— a proof print which closely matches the gloss of the final surface-finished print product.

NOTE 3 If the substrate fails this test, it is in all likelihood not environmentally stable and thus not eligible for

certification.

Table 1 — CIELAB coordinates, gloss, and tolerances for unprinted proofing substrate types

a a a b
Proofing substrate type L* a* b* Gloss
Glossy white ≥ 95 0 ± 2 0 ± 2 61 ± 15
Semi-matte white ≥ 95 0 ± 2 0 ± 2 35 ± 10
Matte white ≥ 95 0 ± 2 0 ± 2 < 25

NOTE The data specified in this table pertain to unprinted proofing substrates, not to be

confused with data pertaining to unprinted production substrate which are given in other

parts of ISO 12647.
Measurement in accordance with 5.3.
Measurement in accordance with 5.5.
4.2.2 Colouration of printed parts

The measurement conditions shall be as specified in 5.3; the digital control strip specified in 5.1

shall be used.
© ISO 2013 – All rights reserved 3
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ISO 12647-7:2013(E)

The CIELAB colour coordinates of the process colour solids shall agree with the pertinent aim values of

the printing condition to be simulated as given by the data (see 4.1.1), within a CIELAB difference of 5;

the contribution of the CIE hue difference to the total CIELAB difference shall not exceed 2,5.

The variability of the colouration across the proof print format is limited by the provision that the

colours of nine measurement locations evenly spaced on the test object (see 5.2.4), which has been

printed without prior modification in view of the printing condition, shall have
— a standard deviation of less than 0,5 each for values of L*, a*, and b*;

— a maximum CIELAB colour difference of 2 between the average value and any one point.

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

primary and secondary colour solids over time, in the dark, shall be limited by the condition that the

CIELAB colour difference that occurs in the first 24 h after the print stabilisation period has elapsed

shall not exceed 1,5.

The light fastness, as determined according to ISO 12040, of the primary colour solids shall not be less than 3.

The CIELAB colour coordinates of the control patches, defined in 5.1 or ISO 12642-2, shall agree with the

pertinent aim values of the printing condition to be simulated as given by the data (see 4.1.1) within the

tolerances specified in Table 2.

If the proofing conditions are such that the simulation of the production printing substrate patch

(C = M = Y = K = 0, i.e. all the components are equal to zero) does require overprinting of the proofing

substrate, the CIELAB deviation tolerance for that patch shall be 3, irrespective of what the pertinent

part of ISO 12647 stipulates for this tolerance.
4.2.3 Repeatability of proof printing

The variability of the proof print primary and secondary colour solids and primary colour midtone

patches from one day to the following shall not exceed a CIELAB colour difference ΔE of 1,5 when the

patches are being measured at the same position on the sheet, and after the vendor-specified warming-

up period and, if necessary, recalibration.

NOTE For certain proofing systems, the same point on a proof print may be formed from a different source

on different days; strictly speaking, this is testing variability not repeatability. For these systems, there is no true

test of repeatability.
4.2.4 Colourant rub resistance

Using the test apparatus and method specified in Annex B, the time required by printed solids to reach

mechanical stability against a rubbing action should not exceed 30 min or the print stabilisation period,

whichever is longer. This test shall be performed for each combination of materials and operating

conditions for which the proofing system is to be certified.

NOTE A period of 30 min was chosen because this is believed to represent the expectation of the average user.

Where the colour (as distinct from the rub resistance of the colourant) takes longer to stabilise, this requirement

can be relaxed.
4 © ISO 2013 – All rights reserved
---------------------- Page: 9 ----------------------
ISO 12647-7:2013(E)
Table 2 — Additional tolerances for control patches
Control patch description Tolerance
Simulated print substrate colour of the production
ΔE ≤ 3
a ab
printing condition
Maximum ΔE ≤ 6
All patches specified in 5.1
Average ΔE ≤ 3
Second half-tone scale composed of the primaries C, M,
Y, roughly replicating the colours of the first scale for
Average ΔH ≤ 1,5
an average printing condition (“grey balance”) (same
number of patches as for colours of the first scale)
Outer gamut patches Average ΔE ≤ 4
Average ΔE ≤ 4
All patches of ISO 12642-2
95 % percentile ΔE ≤ 6

NOTE 1 The tolerances pertain to the deviation of the proof values from the values of the characterization data of the

printing condition to be simulated.

NOTE 2 The specification of ΔE tolerances lower than 3 is presently not practical due to poor inter-instrument agreement.

NOTE 3 If the final proof print is subjected to surface finishing, the final colours might deviate significantly from those

of the unfinished print. See also Note 2 in 4.2.1. In this case, a new proofer or simulation profile or other adjustments are

required.

Required only where the proofing substrate is not identical with the production printing substrate.

4.2.5 Ink set gloss

The gloss of solid tone colours should be visually similar to that of the production print to be simulated.

The ink set gloss may be specified if deemed necessary; see 5.5 for the method.

NOTE If the gloss of the proof print is substantially changed by the applied colourants, a surface-finishing

step might improve the situation. See 4.2.2.
4.2.6 Tone value reproduction limits

Tints intermediate between the (simulated) substrate white and solid shall transfer onto the proof in

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

limits of the printing condition to be simulated; see the pertinent part of ISO 12647 for this information.

NOTE It is good prepress practice that no image parts need to rely on tone values outside of the tone value

reproduction limits of the production printing process.
4.2.7 Tone value

In addition to the requirements of 4.2.2, the single-colour CMYK patches shall not deviate in tone value

(measured colourimetrically) from those of the aim characterisation data by more than 5 % in tone

value. For the calculation of tone values from measured and characterisation CIE data, use the method

described in 5.4.
4.2.8 Reproduction of vignettes

The test objects specified in 5.2.2 shall show no easily visible steps within the tone value reproduction

limits (see 4.2.6), if viewed under ISO viewing condition P1 in accordance with ISO 3664.

© ISO 2013 – All rights reserved 5
---------------------- Page: 10 ----------------------
ISO 12647-7:2013(E)
4.2.9 Image register and resolving power

The maximum deviation between the image centres of any two printed colours shall not be larger than

0,05 mm. The resolving power of the proof print shall be such that C, M, K positive, non-serif, type of

2-point size, reverse (negative) of 8-point size, and 2-point reverse line are legibly reproduced; the test

object specified in 5.2.3 shall be used. The above requirements shall not apply to rough or mechanically

unstable substrates such as newsprint and to cases where the tolerances for production printing are

substantially greater than 0,05 mm.

NOTE 1 This condition usually corresponds to an output addressability of at least 100 pixels per centimetre.

NOTE 2 This condition includes the effects of colourant migration, if at all present.

4.2.10 Margin information

Every digital proof shall bear a human-readable commentary line printed on a margin where the

proofing system designation, the colourant and substrate material types, the printing condition to be

simulated, the colour management profile(s) used, and the time and date are given.

NOTE 1 For ink-jet printers, it is useful to print a nozzle test line next to the commentary line so that it is

possible to ascertain in retrospect that all nozzles were working.
NOTE 2 In some cases of recalibration, it is useful to reprofile the proofer.
4.2.11 Gamut

For each printing condition to be simulated, the 226 outer gamut patches of ISO 12642-2 shall be proof

printed. The average CIELAB 1976 colour difference between actual and aim values for those patches

shall not exceed 4; see also Table 2. See Annex C for the list of outer gamut patches of ISO 12642-2.

5 Test methods
5.1 Control strip

On every proof, print a CMYK digital control strip at the output intent of the printing condition to be

simulated. The control elements identified in the list below should be included while keeping the total

number of patches within reasonable limits. To provide compatibility with characterisation data, as

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

the control patches such that the following control patch types are covered:

a) solid tones of the chromatic primaries and their secondaries C,M,Y,R,G, and B (6 patches);

b) mid- and shadow tones of the chromatic primaries and their secondaries C,M,Y,R,G, and B (12 patches);

c) black (K) only half-tone scale with a minimum of six steps that includes the solid;

d) CMY overprint half-tone scale having the same number of steps as the scale in c) that approximately

replicates, for an average printing condition, the CIELAB values of the black only scale defined in c);

e) selection of critical tertiary colours such as flesh tones, brown, aubergine, violet (e.g. 15 patches);

f) simulated print substrate colour of the production printing condition (1 patch).

NOTE 1 There are two practical definitions for grey which are sometimes contradictory:

— “A colour having the same a* and b* CIELAB values as the print substrate”;
— “A colour having the same a* and b*
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Graphic technology - Process control for the production of half-tone colour separations,

proof and production prints - Part 7: Proofing processes working directly from digital data

Technologie graphique - Contrôle des processus de confection de sélections couleurs

tramées, d'épreuves et de tirages - Partie 7: Processus d'épreuve travaillant directement

à partir de données numériques
Ta slovenski standard je istoveten z: ISO 12647-7:2013
ICS:
37.100.01 *UDILþQDWHKQRORJLMDQD Graphic technology in
VSORãQR general
SIST ISO 12647-7:2014 en

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

---------------------- Page: 1 ----------------------
SIST ISO 12647-7:2014
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SIST ISO 12647-7:2014
INTERNATIONAL ISO
STANDARD 12647-7
Second edition
2013-07-01
Graphic technology — Process
control for the production of half-
tone colour separations, proof and
production prints —
Part 7:
Proofing processes working directly
from digital data
Technologie graphique — Contrôle des processus de confection de
sélections couleurs tramées, d’épreuves et de tirages —
Partie 7: Processus d’épreuve travaillant directement à partir de
données numériques
Reference number
ISO 12647-7:2013(E)
ISO 2013
---------------------- Page: 3 ----------------------
SIST ISO 12647-7:2014
ISO 12647-7:2013(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2013

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

or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior

written permission. Permission can be requested 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 2013 – All rights reserved
---------------------- Page: 4 ----------------------
SIST ISO 12647-7:2014
ISO 12647-7:2013(E)
Contents Page

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

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

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

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

3 Terms and definitions ..................................................................................................................................................................................... 1

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

4.1 Data files, simulation of screens............................................................................................................................................... 2

4.2 Proof print ................................................................................................................................................................................................... 3

5 Test methods ............................................................................................................................................................................................................. 6

5.1 Control strip .............................................................................................................................................................................................. 6

5.2 Additional test objects ...................................................................................................................................................................... 7

5.3 Colour measurement ......................................................................................................................................................................... 7

5.4 Measurement of tone values by tristimulus colourimeter or spectrocolourimeter ................... 8

5.5 Measurement of gloss ....................................................................................................................................................................... 8

5.6 Visual appraisal of proof-press-print matches ............................................................................................................ 8

Annex A (normative) Certification .......................................................................................................................................................................... 9

Annex B (normative) Rub resistance of the proof colourant ...................................................................................................11

Annex C (normative) Outer gamut patches.................................................................................................................................................14

Annex D (informative) Organisational certification routines for visual appraisal of proof-print

press-print matches .......................................................................................................................................................................................20

Bibliography .............................................................................................................................................................................................................................22

© ISO 2013 – All rights reserved iii
---------------------- Page: 5 ----------------------
SIST ISO 12647-7:2014
ISO 12647-7:2013(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.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directives

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. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received. www.iso.org/patents

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.
The committee responsible for this document is ISO/TC 130, Graphic technology.

This second edition cancels and replaces the first edition (ISO 12647-7:2007), of which it constitutes a

minor revision with the following changes:

— clear up the subject matter on certification issues to comply with the ISO requirements;

— update of references.

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
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Introduction

ISO 12647-1 serves to provide definitions, the general principles, the general order, the material to be

covered in ISO 12647-2 to ISO 12647-7, the definition of the data, the measurement conditions, and the

reporting style.

This part of ISO 12647 relates to the subject of digital proofing and establishes proofing requirements

for the most stringent part of the printing and publishing market.

This part of ISO 12647 mainly lists values or sets of values, and their tolerances, of the primary parameters

specified in ISO 12647-1, especially for digital proof printing. Primary parameters that define a printing

condition include the screening parameters, where applicable, the colours of the solids, the colour of the

print substrate, colours intermediate between these and the tone value increase curve. Adherence to

these values essentially ensures that a grey, which at the colour separation stage was composed for a

particular printing condition, also prints as a grey colour in proofing and printing. Remaining deviations

from grey due to differences in trapping can then be removed by adjusting the colouration within the

tolerances provided. This part of ISO 12647 further specifies test methods for those properties of digital

proof prints and their substrates that are considered relevant for stable and reliable conditions, and

thus for a certification procedure.

The graphic technology industry makes extensive use of proofing to predict the rendering of digital

data files by a wide variety of high-definition, high-quality off-press printing processes and applications.

Each prediction is based on a characterisation data set that defines a particular printing condition.

Typically, the specified printing condition is defined through an International Color Consortium (ICC)

profile or the associated characterisation data set, both of which relate source data and colourimetrically

defined printed colour. Such data may be derived from printing conditions conforming to the pertinent

process standard of the ISO 12647 series by industry trade groups or individuals.

The purpose of a proof print is to simulate the visual characteristics of the finished production print

product as closely as possible. In order to visually match a particular printing condition, proofing

processes require a set of parameters to be specified that are not necessarily identical to those put

forward in ISO 12647-1 or another part of ISO 12647. This is caused by differences in colourant spectra

or phenomena such as gloss, light scatter (within the print substrate or the colourant), and transparency.

In such cases, it is also found that spectrocolourimetry takes precedence over densitometry.

Another problem area is the matching of a double-sided production print on a lightweight printing substrate,

such as often used in heat-set web and publication gravure printing, to a digital proof on a nearly opaque

substrate. If the proof was produced using a colour management profile based on measurements with white

backing, there will be an unavoidable visual and measurable difference between the proof on the one hand

and the production print placed on black on the other hand. A black backing is required for double-sided

production printing on non-opaque prints, as specified in the pertinent parts of ISO 12647. The possible

occurrence of such differences needs to be well communicated, in advance, to all parties concerned.

Historically, there has been no consistency in the way that either the characterisation data or the criteria

and limits for a satisfactory match have been provided. This has led to significant redundancy and

inconsistencies in the evaluation of proofing systems for different, but similar, applications, and a cost

and time burden on the industry. This International Standard therefore attempts to provide guidance in

this area by providing specifications and associated testing procedures.

Annex A gives the requirements for the digital proof prints listed in the main body of this part of

ISO 12647; these are weighted with respect to their relevance in two typical situations:

— requirements with which a proof print, made for a particular printing condition, must comply if it

is to be referenced in a contract between the printer and the provider of the digital data (“Certified

Proofing System”);

— requirements with which a vendor’s proofing system, comprising hardware and software, must

comply if it is to be considered capable of reliably producing digital contract proofs for a particular

printing condition (“Certified Proofing System”).
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INTERNATIONAL STANDARD ISO 12647-7:2013(E)
Graphic technology — Process control for the production of
half-tone colour separations, proof and production prints —
Part 7:
Proofing processes working directly from digital data
1 Scope

This part of ISO 12647 specifies requirements for systems that are used to produce hard-copy

digital proof prints intended to simulate a printing condition defined by a set of characterisation

data. Recommendations are provided with regard to appropriate test methods associated with these

requirements.

This part of ISO 12647 is independent of the method used to produce a digital proof print.

2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are

indispensable for its application. For dated references, only the edition cited applies. For undated

references, the latest edition of the referenced document (including any amendments) applies.

ISO 3664, Graphic technology and photography — Viewing conditions

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

beam, TAPPI method

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

xenon arc light

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

technology (TIFF/IT)

ISO 12640-1, 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 12647-1:2004, Graphic technology — Process control for the production of half-tone colour separations,

proof and production prints — Part 1: Parameters and measurement methods

ISO 13655, Graphic technology — Spectral measurement and colorimetric computation for graphic arts images

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
digital proof

soft proof or hard-copy proof produced directly from digital data, on a display or a substrate

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3.2
digital proof print
digital hard-copy proof
digital proof produced as a reflection copy on a proofing substrate
3.3
proofing substrate
printing substrate used for hard-copy proofing processes
3.4
half-tone proof print

proof print made using the same screening technology (generally centre-weighted half-tone dots) as the

intended production printing

Note 1 to entry: This is done to attempt to produce (and therefore check for the existence of) the same screening

artefacts, such as rosettes, moiré, or aliasing patterns, as expected in the corresponding production print. One

possibility is to base proofing on the bitmap produced on the production plate or film setter.

3.5
print stabilisation period

time elapsed since the production of a proof print until a stable colour is achieved

Note 1 to entry: This property is to be specified by the manufacturer.
4 Requirements
4.1 Data files, simulation of screens
4.1.1 Data delivery

Digital proofing systems should accept digital data delivered as PDF/X data files as defined in ISO 15930

(all parts) or TIFF/IT files as defined in ISO 12639. Where TIFF/IT files are used, colour information

shall be included using tag 34675 or tag 34029 as defined in ISO 12639.

NOTE PDF/X requires that the intended printing condition be indicated. Where the intended printing

condition is included in the registry of characterisations maintained by the International Color Consortium (ICC)

and the digital data are cyan-magenta-yellow-key (black) (CMYK), the name used in the ICC registry is usually

used for identification in lieu of including an ICC output profile. If the intended printing condition is not included

in said registry, PDF/X requires that an ICC output profile be included. If the data are other than CMYK, the data

are required to be defined colourimetrically using an ICC input profile or another mechanism and an ICC CMYK

output profile is required to be included; the rendering intent to be used with the output profile is required to be

communicated.
4.1.2 Screen frequency

Half-tone proofs should have the same nominal screen frequencies (screen rulings) as the production

press print to be simulated.
4.1.3 Screen angle

Half-tone proofs should have the same screen angles as the production print to be simulated.

4.1.4 Dot shape and its relationship to tone value

Half-tone proofs should have the same general dot shape as the production print to be simulated.

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4.2 Proof print
4.2.1 Proofing substrate colour and gloss

The digital proofing substrate should, if possible, be the same as the substrate to be used for production

printing. Where this is not possible, the digital proofing substrate should have the same gloss and CIELAB

a* and b* values as the intended production printing substrate within the tolerances listed in Table 1.

Where the characteristics of the printing substrate to be used for production printing are not exactly

known, a suitable proofing substrate conforming to one of the three types given in Table 1 shall be used.

The proof and production printing substrates should ideally have similar UV responses under the

recommended measurement conditions.

Annex A gives requirements for a digital proof print that are weighted with respect to their relevance.

Where the production printing substrate is not identical to the proofing substrate, the colour of the

latter shall not vary by more than a CIELAB 1976 colour difference of 1,5 when successively subjected to

the following storage conditions in the dark:
a) 24 h at 25 °C and a relative humidity of 25 %;
b) 24 h at 40 °C and a relative humidity of 80 %;
c) one week at 40 °C and a relative humidity of 10 %.

For the same proofing substrate, the variability of colour under light exposure is limited by the condition

that the light fastness, as determined in accordance with ISO 12040, shall not be less than 3.

NOTE 1 A light fastness step of 3 corresponds approximately to a 300 d exposure to normal office lighting.

NOTE 2 In production printing, if the final print product is subjected to surface finishing, this might significantly

affect the gloss and often also the colour. In critical cases, the result of the colour separation stage is best judged

by means of a proof that closely matches the gloss of the final surface-finished print product. For processes with

off-press finishing, in order to facilitate the matching of the production image to the proof image at the make-

ready stage, it is useful to provide the press operator with two proof prints:

— a proof print whose gloss matches that of the (unfinished) production print substrate;

— a proof print which closely matches the gloss of the final surface-finished print product.

NOTE 3 If the substrate fails this test, it is in all likelihood not environmentally stable and thus not eligible for

certification.

Table 1 — CIELAB coordinates, gloss, and tolerances for unprinted proofing substrate types

a a a b
Proofing substrate type L* a* b* Gloss
Glossy white ≥ 95 0 ± 2 0 ± 2 61 ± 15
Semi-matte white ≥ 95 0 ± 2 0 ± 2 35 ± 10
Matte white ≥ 95 0 ± 2 0 ± 2 < 25

NOTE The data specified in this table pertain to unprinted proofing substrates, not to be

confused with data pertaining to unprinted production substrate which are given in other

parts of ISO 12647.
Measurement in accordance with 5.3.
Measurement in accordance with 5.5.
4.2.2 Colouration of printed parts

The measurement conditions shall be as specified in 5.3; the digital control strip specified in 5.1

shall be used.
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The CIELAB colour coordinates of the process colour solids shall agree with the pertinent aim values of

the printing condition to be simulated as given by the data (see 4.1.1), within a CIELAB difference of 5;

the contribution of the CIE hue difference to the total CIELAB difference shall not exceed 2,5.

The variability of the colouration across the proof print format is limited by the provision that the

colours of nine measurement locations evenly spaced on the test object (see 5.2.4), which has been

printed without prior modification in view of the printing condition, shall have
— a standard deviation of less than 0,5 each for values of L*, a*, and b*;

— a maximum CIELAB colour difference of 2 between the average value and any one point.

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

primary and secondary colour solids over time, in the dark, shall be limited by the condition that the

CIELAB colour difference that occurs in the first 24 h after the print stabilisation period has elapsed

shall not exceed 1,5.

The light fastness, as determined according to ISO 12040, of the primary colour solids shall not be less than 3.

The CIELAB colour coordinates of the control patches, defined in 5.1 or ISO 12642-2, shall agree with the

pertinent aim values of the printing condition to be simulated as given by the data (see 4.1.1) within the

tolerances specified in Table 2.

If the proofing conditions are such that the simulation of the production printing substrate patch

(C = M = Y = K = 0, i.e. all the components are equal to zero) does require overprinting of the proofing

substrate, the CIELAB deviation tolerance for that patch shall be 3, irrespective of what the pertinent

part of ISO 12647 stipulates for this tolerance.
4.2.3 Repeatability of proof printing

The variability of the proof print primary and secondary colour solids and primary colour midtone

patches from one day to the following shall not exceed a CIELAB colour difference ΔE of 1,5 when the

patches are being measured at the same position on the sheet, and after the vendor-specified warming-

up period and, if necessary, recalibration.

NOTE For certain proofing systems, the same point on a proof print may be formed from a different source

on different days; strictly speaking, this is testing variability not repeatability. For these systems, there is no true

test of repeatability.
4.2.4 Colourant rub resistance

Using the test apparatus and method specified in Annex B, the time required by printed solids to reach

mechanical stability against a rubbing action should not exceed 30 min or the print stabilisation period,

whichever is longer. This test shall be performed for each combination of materials and operating

conditions for which the proofing system is to be certified.

NOTE A period of 30 min was chosen because this is believed to represent the expectation of the average user.

Where the colour (as distinct from the rub resistance of the colourant) takes longer to stabilise, this requirement

can be relaxed.
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Table 2 — Additional tolerances for control patches
Control patch description Tolerance
Simulated print substrate colour of the production
ΔE ≤ 3
a ab
printing condition
Maximum ΔE ≤ 6
All patches specified in 5.1
Average ΔE ≤ 3
Second half-tone scale composed of the primaries C, M,
Y, roughly replicating the colours of the first scale for
Average ΔH ≤ 1,5
an average printing condition (“grey balance”) (same
number of patches as for colours of the first scale)
Outer gamut patches Average ΔE ≤ 4
Average ΔE ≤ 4
All patches of ISO 12642-2
95 % percentile ΔE ≤ 6

NOTE 1 The tolerances pertain to the deviation of the proof values from the values of the characterization data of the

printing condition to be simulated.

NOTE 2 The specification of ΔE tolerances lower than 3 is presently not practical due to poor inter-instrument agreement.

NOTE 3 If the final proof print is subjected to surface finishing, the final colours might deviate significantly from those

of the unfinished print. See also Note 2 in 4.2.1. In this case, a new proofer or simulation profile or other adjustments are

required.

Required only where the proofing substrate is not identical with the production printing substrate.

4.2.5 Ink set gloss

The gloss of solid tone colours should be visually similar to that of the production print to be simulated.

The ink set gloss may be specified if deemed necessary; see 5.5 for the method.

NOTE If the gloss of the proof print is substantially changed by the applied colourants, a surface-finishing

step might improve the situation. See 4.2.2.
4.2.6 Tone value reproduction limits

Tints intermediate between the (simulated) substrate white and solid shall transfer onto the proof in

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

limits of the printing condition to be simulated; see the pertinent part of ISO 12647 for this information.

NOTE It is good prepress practice that no image parts need to rely on tone values outside of the tone value

reproduction limits of the production printing process.
4.2.7 Tone value

In addition to the requirements of 4.2.2, the single-colour CMYK patches shall not deviate in tone value

(measured colourimetrically) from those of the aim characterisation data by more than 5 % in tone

value. For the calculation of tone values from measured and characterisation CIE data, use the method

described in 5.4.
4.2.8 Reproduction of vignettes

The test objects specified in 5.2.2 shall show no easily visible steps within the tone value reproduction

limits (see 4.2.6), if viewed under ISO viewing condition P1 in accordance with ISO 3664.

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4.2.9 Image register and resolving power

The maximum deviation between the image centres of any two printed colours shall not be larger than

0,05 mm. The resolving power of the proof print shall be such that C, M, K positive, non-serif, type of

2-point size, reverse (negative) of 8-point size, and 2-point reverse line are legibly reproduced; the test

object specified in 5.2.3 shall be used. The above requirements shall not apply to rough or mechanically

unstable substrates such as newsprint and to cases where the tolerances for production printing are

substantially greater than 0,05 mm.

NOTE 1 This condition usually corresponds to an output addressability of at least 100 pixels per centimetre.

NOTE 2 This condition includes the effects of colourant migration, if at all present.

4.2.10 Margin information

Every digital proof shall bear a human-readable commentary line printed on a margin where the

proofing system designation, the colourant and substrate material types, the printing condition to be

simulated, the colour management profile(s) used, and the time and date are given.

NOTE 1 For ink-jet printers, it is useful to print a nozzle test line next to the commentary line so that it is

possible to ascertain in retrospect that all nozzles were working.
NOTE 2 In some cases of recalibration, it is useful to reprofile the proofer.
4.2.11 Gamut

For each printing condition to be simulated, the 226 outer gamut patches of ISO 12642-2 shall be proof

printed. The average CIELAB 1976 colour difference between actual and aim values for those patches

shall not exceed 4; see also Table 2. See Annex C for the list of outer gamut patches of ISO 12642-2.

5 Test
...

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