Iarigai lanat communication on visual perception and colour management montreal paper 2010

1. Communication within the value chain of paper-print: visual perception
and colour management on commercial publication paper grades.
Luc Lanat
Stora Enso Publication Paper, Corbehem mill, Rue de Corbehem, 62117 BREBIERES, FRANCE
luc.lanat@storaenso.com
Key Words
Quality, paper, printing, colour gamut, whiteness.
Short Abstract
Paper and forest products are renewable, recyclable, sustainable, and bring emotions to end-user.
Emotions and quality images are linked. This topic motivates active research.
In Communication within the value chain paper-printing, several misunderstandings appear:
* Misunderstandings due to differences between printing equipments and papermaking equipments.
* Misunderstandings due to differences in lighting conditions between papermakers and printers.
* Misunderstandings between colour management prepress specifications and visual perception of white
paper colour by itself.
* Misunderstandings on printing relevant properties. Which paper properties are relevant for paper during
printing?
* Misunderstandings motivated by different interests between stakeholders: printing machine suppliers,
papermakers suppliers, materials and software suppliers.
To clarify these misunderstandings, main conclusions of this paper are:
* Perception of paper whiteness, evaluated visually through panels indoor, but close to Nordic daylight
showed that Whiteness measurement is superior to Brightness.
* Printing at constant target density, colour gamut, calculated as per C* sum reported in literature earlier,
gave deceiving results. It is suggested that PPS roughness, although primitive, is more distinctive than
shade references to select the right colour management profile, mainly linked to a paper type.
Definitely, further work is here needed to come to any conclusion on Colour Gamut potential.
* Colour Gamut discussions should integrate data made available by papermakers, as described in ISO
NWI 15397 proposed standard and also detailed in this paper. Papermakers of Paperdam working group
agreed to make available paper white point and publicly available characterization data to be used with
their grades to their best knowledge. This is not a guarantee for “conformance” or “standardized
printing”, but of course it is a preferred starting point and should bring printing consistency.
* To reach targeted colours, ISO specified paper colour targets do not cover all market conditions. There
is a clear need for evaluation of paper white point as a colour for best colour management calculations
and avoid colour shifts versus targets.
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2. Communication within the value chain of paper-print: visual perception
and colour management on commercial publication paper grades.
Luc Lanat
Stora Enso Publication Paper, Corbehem mill, Rue de Corbehem, 62117 BREBIERES, FRANCE
luc.lanat@storaenso.com
1. Introduction
Nowadays, paper and thus papermaker’s efforts must concentrate on what they do best: offering emotions
and images of quality to the end-user. Emotions and quality images are linked. This topic motivates active
research.
We showed in a previous paper (Kolseth, Lanat, Sävborg, 2009) the importance of paper optics and
equipments in printing evaluations and also how optical dot gain, because intrinsic paper property, could
introduce incorrect dot gain evaluations in Sheet Fed Offset.
In another unpublished internal study, we verified the influence of Stora Enso Press Selection paper
grades on Colour Gamut in the a* and b* plane on samples printed in rotogravure. Results were in line
with usual paper classification. The ranking, namely from low to high colour gamut in the a* and b*
plane was: Improved News 52 gsm, White Improved News 55 gsm, SC B 56, SC A 56 gsm, SC A+ 56
gsm, SC A ++ 54 gsm, LWC 54 gsm, LWC 57 gsm, LWC + 70 gsm. This ranking was close to L*
coordinate ranking and encouraged us to study further the a* and b* plane, as an approach to colour
gamut evaluation.
We present here internal studies on:
* Paper whiteness and perception evaluated through panels.
* Colour Gamut of commercial papers both in Heat Set Web Offset and Gravure printing through specific
but reproducible and consistent printing trials.
Also, this paper is motivated by developments of Standardization within ISO TC 130 (Printing) and TC 6
(Paper). A list of print relevant paper properties was published recently by VDMA Germany and by
virtually all printing market players. (Papierkennwerte/Characteristic paper values, 2009). As a follow up,
ISO WD 15397 “Communication of optical and surface properties of printing substrates - Graphic papers
for rotogravure, heat-set web offset, offset sheets, proofing” is in development.
The objective of this paper is three-fold:
* To contribute to use in the market and within mills optical paper measurements which match visual
perception with human eye in usual home-office conditions.
* To contribute to develop methods to quantify paper performance when evaluating colour coordinates of
the CMY-RGB hexagon.
* To give ground and encourage further standardization developments.
2. Methods
Visual panel for paper whiteness perception
We asked a group of 12 experienced people to rank a set of papers from the markets from Improved News
up to WFC (Wood Free Coated) (Jordan, O’Neill 1991). The test was operated in Falun mid-Sweden
indoor but behind a window under noon overcast Nordic daylight. We compared this ranking with several
available optical laboratory properties (Brightness D65, C Brightness, Whiteness, Colour L*, a*, b*.
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3. Equipments
We used an Elrepho spherical spectrophotometer (d/0°), available in paper industry and i-one X-Rite
angular spectrophotomer (45°/0°) used in graphic industry for printing evaluations.
Elrepho, is classical equipment for papermakers, and allows to follow deviations due to UV content.
Routines are available to measure Colour L*, a*, b* D50, with the UV calibration of C illuminant. See
ISO 5631-3.
Colour Management and Colour Gamut calculation
Colour rendering is an important component of print quality, the other being detail rendering. The size of
the colour gamut depends on both printing process and material including paper type. A larger colour
gamut, or colour range, is commonly accepted as a potentially better print quality. It is however not
generally established how much larger one specific colour gamut should be to be perceived as a
significantly better print quality. One straightforward approach was made by Kurt Schläpfer (2000), who
proposed a simple classification of colour gamut’s of different printing processes. He suggested that the
colour gamut of any printing process (for a given combination of ink strength and substrate) is primarily
determined by the chroma (saturation) values of the primary colours - Cyan C, Magenta M, Yellow Y -
and the secondary colours - Red (M+Y), Green (C+Y) and Blue (C+M).
Using this approach, he suggested that the colour gamut of a printing process can be described by one
single number, the gamut area in the a* b*-plan. The gamut area is defined by Chroma (C*) and hue (h*)
angle values, but Schläpfer showed that the area correlates very well with the sum of the Chroma values.
Therefore the Chroma sum (C* Sum) is used in this paper as a characterization of the colour gamut.
Chroma sum is given by Equation 1 where n is the six primary and secondary colours. Schläpfer
suggested steps of 50 units in Chroma sum to identify different categories.
This calculation does not take L* coordinate in consideration, while ISO 12647 series does. This
approach is a comparative tool and an approximation and cannot be used yet as a tool to evaluate paper as
such.
The use of this calculation should be linked to consistent and reproducible printing conditions. This is
what we focused on. We used internal printing forms, with standard colour patches, FOGRA Media
Wedge or ECI 2002.
Equation 1 ( ) ( ) !=
3
6
* C Sum a b
= +
1
2 2
n
*
n
*
n
Printing trials HSWO and Gravure
For each presented study, we performed our printing trials keeping most parameters constant, and
concentrated on paper changes.
Target ink densities were kept constant, coated and uncoated papers being printed at different ink
densities, as usual. Inks were industrial inks.
HSWO trials were printed at KCL pilot plant in Finland.
Gravure trials were specifically prepared by industrial printer and operated in France.
3. Results
Study 1. Whiteness panel ranking of European commercial papers, indoor but Nordic light
Figure 1 gives the results of the ranking panel.
The x-axis gives panel visual perception of papers, lowest to the left to highest to the right.
Measured whiteness, brightness and fluorescence are compared with the results from the ranking panel.

4. Whiteness-Brightness scale on left, Fluorescence scale on right.
LWC 54 gsm
SC A++ 57 gsm
4
110
100
90
80
70
60
50
40
Offset News 52 gsm
Improved News 52 gsm
SC A 56 gsm
SC A 56 gsm
SC A 56 gsm
Improved News 52 gsm
LWC 57 gsm
LWC 57 gsm
Improved News 52 gsm
SC A+ 56 gsm
LWC 57 gsm
SC A ++ 51 gsm
SCA++ 57 gsm
MWC 80 gsm
WF Silk 115 gsm
LWC 70 gsm
MWC 70 gsm
100
90
80
70
60
50
40
30
20
10
0
Fluorescence, D65/10° D65-Brightness CIE-Whiteness, C/2°
Figure 1. Visual Whiteness perception under indoor conditions but Nordic overcast daylight, papers in x-axis
in order of visual ranking.
* Whiteness C values range from 40 to 110, while D65 Brightness values range from 60 to 95. Whiteness
is thus more distinctive.
* For Whiteness values above 60, Whiteness C gives closer match than D65 Brightness to panel ranking.
* For Whiteness values below 60, the shade and fluorescence become more evident for the panel than
Whiteness as such. This is logical, shade is more important for less white papers and visual evaluations
may differ due to shade (b* values in particular on the yellow-blue axis) and fluorescence.
Study 2. ISO12647-2 targets and evaluation of Colour Gamut at full tones in Heat Set Web Offset
MWC papers from European market 2009
This study gathers HSWO MWC papers from 70 to 115 gsm from European market. Printing was
operated at KCL printing pilot plant in April 2009 under consistent conditions and approaching daily
practice at printing plants, namely at constant target densities. Tested samples were printed at following
target densities: Black 1,70 / Cyan 1,50 (+/-0,05) / Magenta 1,30 / Yellow 1,20 and kept constant for all
grades. The out coming web temperature was kept constant at 130 °C. Target densities were not
optimised to reach CIELAB values for primary and secondary colours as specified in ISO 12647-2.
The measurements were made on prints over a white backing with a Gretag Spectrolino
spectrophotometer without polarising filter. The calculations were made with the D50 illuminant and the
2° observer weight functions.
Our goal was to position the colour gamut variations versus ISO-ECI-FOGRA targets described in
characterization data for the related grades and to evaluate colour gamut to rank papers with possible
links to paper properties.
Figure 2abcd shows colour coordinates for white paper, black print and primary and secondary colours.
Tolerances allowed by ISO 12647-2 are shown as circles. Full circle is centered on the shades target of
ISO 12647-2 and dotted circle is centered on the average of all papers.

5. All papers ISO12647-2 (1&2)
All papers ISO12647-2 (1&2)
Yellow Red (M+Y)
All papers ISO12647-2 (1&2)
5
Paper Black
20
15
10
5
0
-5
-10
-15
-20
-20 -15 -10 -5 0 5 10 15 20
20
15
10
5
0
-5
-10
-15
-20
All papers ISO12647-2 (1&2)
-20 -15 -10 -5 0 5 10 15 20
Figure 2a Colour coordinate b* versus a* for white paper and black print.
Cyan Magenta
20
15
10
5
0
-5
-10
-15
-20
50 55 60 65 70 75 80 85 90
-30
-35
-40
-45
-50
-55
-60
-65
-70
All papers ISO12647-2 (1&2)
-60 -55 -50 -45 -40 -35 -30 -25 -20
Figure 2b Colour coordinate b* versus a* for cyan and magenta.
70
65
60
55
50
45
40
35
30
50 55 60 65 70 75 80 85 90
110
105
100
95
90
85
80
75
70
All papers ISO12647-2 (1&2)
-20 -15 -10 -5 0 5 10 15
Figure 2c Colour coordinate b* versus a* for yellow and red (M+Y).

6. Blue (C+M)
All papers ISO12647-2 (1&2)
6
-30
-35
-40
-45
-50
-55
-60
-65
-70
5 10 15 20 25 30 35 40
Green (C+Y)
45
40
35
30
25
20
15
10
5
All papers ISO12647-2 (1&2)
-85 -80 -75 -70 -65 -60 -55 -50 -45
Figure 2d Colour coordinate b* versus a* for green (C+Y) and blue (C+M).
Figure 3 presents the Colour Gamut of the printed result by one single number, the Chroma sum or C*
sum, as per Equation 1.
Figure 3. Chroma sum C* at 100% tone. HSWO European papers 70-115 gsm.
Figure 3 shows a tendency towards that higher grammage offers better Chroma sum. As expected, higher
grammages and smoother papers give better results. As expected also, when comparing 115 gsm Gloss
with 115 gsm Silk, Silk paper being less smooth shows indeed lower C* sum. Chroma sum is intended to
be useful as a comparison between and within paper type, but the difference within paper types is here
negligible.
Study 3. Gravure trial 2010 at industrial printer to compare LWC and LWC high brightness from
same mill
We run another trial to compare 2 papers rather close for end-user, namely only different in brightness-shade
and in touch and feel properties (silk touch). The ECI 2002 colour patches (more than 1600) were
printed. Paper properties are described in Table 1 and results in Figure 4a and 4b. Table 1 gives the delta
b* measured with a papermaker equipment with D65 illuminant, namely 6,6. Figure 4 data use a printer
equipment with D50 illuminant.

7. gsm Gloss PPS roughness Bulk L*/a*/b* D65
7
LWC Silk
high brightness
60
55 0,97 0,8 91/0,1/-4
LWC Gloss 57 48 0,74 0,8 90/-0,8/2,6
Table 1 Paper properties Gravure trial LWC Silk high brightness versus LWC Gloss
Figure 4a Colour coordinates at 100% tone Figure 4b Colour coordinates at 40% tone.
Figure 4 shows that at full tone, the Colour Gamut, calculated as C* sum, is close for both papers (382
versus 376). At 40 %, they are also exactly equivalent (146 versus 146), but shifted about 5 units in the b*
axis.
4. Discussion
Communication within the value chain of paper-print
It is important to distinguish paper visual perception and paper optics needed to fine-tune colour
parameters during printing. These concepts are different, targets, equipments, people in charge are
different, but both informations are needed.
There are also several misunderstandings to clarify in communication within the value chain.
* Misunderstandings due to differences between printing equipments and papermaking equipments.
Both papermaking and printing processes are industrial processes and do need different methods. They do
not measure the same processes. As an example, printers optical equipments geometry is 45°/0° or 0°/4
5°, this satisfactory and widely used, while papermakers use d/0° more suitable, because more accurate
for them.
* Misunderstandings due the differences in lighting conditions between papermakers and printers.
Papermakers use D65 illuminant, needed to evaluate high brightness grades, and mostly Xenon light
sources. Printers use D50 illuminant for historical reasons (Jordan, 2006).
The new CIE illuminant, ID65 (indoor D65), Nordic daylight behind a window, (Jordan, 2002 and
Gombos, 2008) is adding even more confusion. We believe, but this must still be proven, that it may be
close to Whiteness calculated with illuminant C and thus would not bring any new information for our
industries.
* Misunderstandings between colour management prepress specifications and visual perception of white
paper colour by itself. The white point of paper is needed as a zero point for colour management software
and characterization data. But each paper grade should have a characterization data independently of its

8. colour or white point. The visual aspect of white paper is a different concept than paper colour
measurement needed for colour management settings.
* Misunderstandings on printing relevant properties. Which paper properties are relevant for paper during
printing? Paper is defined through a very long list of physical and chemical parameters, and depending on
the end-use, some properties are relevant and other not. Thousands of data are indeed available within the
papermaking process and it is a must to identify those relevant.
* Misunderstandings motivated by different interests between stakeholders: printing machine suppliers,
papermakers suppliers, materials and software suppliers. All want to promote quality and consistent
printing and standardization is an excellent tribune for this. But they all have different interests and
vocabulary. Papermaking process is heavy industry and consistency is needed for our operations and costs
even more than for our paper users. Also, papermakers develop, beside the printers’ needs, what their
customers, publishers and advertisers are asking, and they all want to differentiate at best costs.
Study 1
Papers with same Brightness D65 / observer 10° differed in visual perception with Whiteness illuminant
C / observer 2°. Whiteness C is here more in accordance with visual ranking and thus preferred.
Whiteness calculation formula integrates already the shade. Other studies showed that b* shade and L*
are most influent on whiteness.
Study 2
We conclude from Figure 2 that variation tolerances allowed in 12647-2 are reached. They are rather
wide and even allow papers ranging from LWC 70 gsm up to WF 115 gsm, Silk and Gloss to be within
the tolerances allowed by the standard.
We also conclude that ISO targets (see figure 2a tests on blank Paper) differ from average of papers
tested. So, there is a clear need for evaluation of paper white point as a colour for best colour management
calculations.
Schläpfer (2000), mentions a 50 points difference as being relevant to differentiate printing processes. It
seems that the calculation may still give too much importance to shade.
We tried to correlate the Figure 3 results with several paper properties. Most relevant were Gloss, PPS
roughness, b* shade, but we could not draw a clear conclusion to link Colour Gamut as calculated above
and a paper property.
Still PPS gave the best tendency and this suggests that PPS may be used, although primitive, to forecast
the potential Colour Gamut, more than anything else. PPS being available easily this would allow to
select the correct paper type and characterization data.
In our example, ISO shade classification as per ISO 12647-2, distinguishes 2 paper types thru 2 shade
classes : (a*=0/b*=-3) for WF Gloss, WF Matt, WF Silk, MWC Gloss, MWC Silk and (a*=-1/b*=3) for
LWC + Gloss, LWC Gloss. PPS below 1 (115 gsm Gloss) or PPS above 1 (70 gsm Gloss) will be more
distinctive.
Definitely, further work is here needed to come to any conclusion on Colour Gamut potential. Colour
Gamut as such is quite difficult to evaluate. To define information capacity of printed matter is the
important issue and depends of colour gamut, but also printing conditions, inks, dot gain, screen ruling,
etc… All this factors need to be addressed. Recent standardization work introduces the concept of
Achievable Colour Gamut, also known as “Process agnostic”, and this is to be supported but worked out.
So, our message is that Colour Gamut discussions should integrate data made available by papermakers,
as described in ISO NWI 15397 and also detailed later in this paper.
Also, papermakers of Paperdam working group agreed to make available paper white point and publicly
available characterization data to be used with their grades to their best knowledge. This is not a
guarantee for “in conformance” or “standardized” printing, but of course it is a preferred starting point
and should bring printing consistency.
Study 3
Study 3 shows again that the white point of paper will influence colour qualities. Colour gamut is not
only a plane in colour space, it is a non-symmetric 3D volume space from black CMYK (overprinting) up
to white end (paper whiteness). Our experience is that, visually, at higher L* values, paper shade a* and
b* values affect more printed colour, reddish paper shade giving warm colour to white human skin and
too bluish paper shade giving "sick" colour to the human face.
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9. Link with ISO Standardization
Numeric data files introduction and need for consistent printing independent of printing equipments and
locations is pushing standardization developments. (McDowell 2006).
Printing industry standards developed within ISO TC 130 do refer to several paper properties, paper being
a widely used printing substrate.
ISO TC 6 Pulp, Paper and Board successfully developed standards to allow papermaking processes to
stay reproducible and reliable within paper mills. They are of course used for paper specifications when
needed.
As mentioned above, an important issue is the prepress white point settings. To determine the colour of
unprinted paper, we recommend using ISO 5631-3 or to approach the results obtained with ISO 5631-3.
Calibration routines are widely available and in operation worldwide. This can be done with either
papermaker's equipments or printer's equipments. Printing equipments differ from equipments used
within paper mills, meant for paper process control. Results of correctly calibrated equipments are often
close, but not always.
Proposal for paper specifications and paper requirements
The use of a paper-based standard is recommended. This includes and starts with paper proofing
substrates.
Paperdam working group is promoting a Standard proposal NWI 15397 on “Communication of optical
and surface properties of printing substrates – Graphic paper for proofing, rotogravure, heat-set web
offset, sheet-fed offset”. This tentative standard gives an extended list of ISO standardized paper
properties as per below:
Print relevant properties for Proofing, Roto, HSWO, SFO:
- Paper mill and brand name.
- Grammage.
- Bulk or specific volume.
- Roughness PPS (Parker-print Surf) for coated grade, Roughness Bendtsen for Mat, Silk or
Uncoated grade. Only PPS for Gravure.
- Gloss. (or classification Gloss, Silk, Matt for Proof substrates).
- Opacity.
- Brightness or Whiteness. For visual evaluation on unprinted paper.
- Colour as per L*, a*, b* D50 (printing conditions). For evaluation of paper white point under
D50 illuminant.
- Colour as per L*, a*, b* D65 (outdoor conditions). For evaluation of unprinted substrate under
D65 illuminant.
- Prepress Colour Management deviations to be expected due to UV content of light.
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Print relevant properties for Roto, HSWO, SFO:
- Prepress information. Publicly available characterization data recommendations.
Print relevant properties for Roto:
- Tensile strength.
Print relevant properties for SFO:
- Resistance to bending (rigidity).
5. Conclusions
Paper whiteness evaluation needs to be addressed, depending of lighting conditions.
We recommend to use Whiteness C illuminant 2° observer as hint to evaluate paper whiteness. Since D65
Brightness 10° is also commercially widely available, linked to commercial decisions, and anyhow useful
for papermaking process monitoring, it is also mentioned in most Technical Data Sheets.
Introducing Indoor and Outdoor Whiteness with reviewed calculations may further do improvements or
simplification:
* Above 420 nm, calculate Indoor and Outdoor Whiteness as per Whiteness D65 to day.
* Below 420 nm, calculate as per illuminant C for Indoor Whiteness and as per illuminant D65 for
Outdoor Whiteness.

10. This concept is under development for next ISO TC 6 meeting in Paris, together with modified CIE
Whiteness calculation for values above 140 (Coppel, 2007).
It is clear that the 12647 paper colour targets have an interest for printing consistency and
standardization. But targets given in these standards are misleading. Market may change and
determination of white point of paper is a must. Colour L*, a*, b* D50 paper data are made available by
papermakers for printers when needed.
Besides this, papermakers will give hints on how to best use their products by recommending best
publicly available paper profiles and characterization data (see Paperdam working group statement).
Achievable Colour Gamut depends of printing process, printing conditions. It does not depend of paper
shade only, but is linked to surface mainly, in less extent to L* values and even less extend to shade (or
fluorescence thus).
Further work is needed to agree on standardized and reproducible methodologies, because this issue is
complex but full of potential. A suggested method could be as follows: print with same conditions (ink,
blankets-cylinder engraving) at several densities. To determine Colour Gamut at a given density, evaluate
Colour Gamut at several densities and extrapolate at the given density.
Quality: “I know it when I see it”. (Guaspari, 1985)
We want paper users to get the full benefit of the daily quality improvements made in our mills.
6. Acknowledgements
We want to acknowledge the contributions by many Stora Enso colleagues, among those we want to
mention Anna Nicander, Torbjörn Wahlström and Frank Werthschulte.
We also acknowledge the fruitful discussion within the so-called Paperdam group. Paperdam is a
working group of technical and printing experts from Burgo, Holmen, Lecta, Myllykoski, Norske, SAPPI,
SCA, Stora Enso, UPM, on printing and paper standardization issues, such as Colour Management.
7. References
Coppel L, Lindberg S, Rydefalk, S. Whiteness assessment of paper samples in the vicinity of upper CIE whiteness
limit, 26th session of the CIE, Beijing, China, pp D1-10. And other Innventia studies.
Gombos, Katalin, Pointer Michael, Sik-Lànyi Cecilia, Schanda Jànos, Tarczali Tünde, 2008, Proposal for an Indoor
Daylight Illuminant. Color Research and application pp 08-25.
Guaspari, John, 1994. Quality, I know it when I see it. Book, AMACOM, American management Association.
Jordan, Byron, O’Neill, M.A. 1991.The whiteness of paper colorimetry and visual ranking. TAPPI 74 (5): 93-101.
Jordan, Byron, 2002. Accurate Colorimetry of fluorescent papers. ISO TC6 WG 3: N 528.
Jordan, Byron, 2003. More thoughts on Illuminants. ISO TC6 WG 3: N 537.
Mc Dowell, David Q., 2006, The Synergistic Relationship between Standards for Data Exchange, Metrology, Process
Control, and Color Management, TAGA Proceedings pp 151-156.
Kolseth Peter, Lanat Luc, Sävborg Örjan. 2009. Printing by numbers on commercial paper grades. Presented at
iarigai conference Stockholm.
Puebla, Claudio, 2003. Whiteness assessment, a primer. Concepts, Determination and Control of Perceived
Whiteness. Axiphos Gmbh, Germany. See www.axiphos.com.
Schläpfer, Kurt, 2000. Classification of Colour Gamut’s of Printing Processes. TAGA Proceedings, pp112-129.
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11. Other references and standards cited
Kolseth Petter, Nicander Anna, 2006 Colour Gamut in Rotogravure, Stora Enso Research Falun Internal report.
Paperdam presentations to ISO TC 6 and TC 130. See www.paperdam.com.
Papierkennwerte in German/Characteristic paper value, Recommended characteristic paper values for communication
within the value chain of paper-print. Initiative of VDAM and Zellcheming 2009-2010. See www.zellcheming.de or
www.vdma.org or www.paperdam.org.
ISO Standards of TC 6 and TC 130 cited
ISO 2470-2. Paper, board and pulps — Measurement of diffuse blue reflectance factor — Part 2: Outdoor daylight
conditions (D65 brightness).
ISO 11476. Paper and board — Determination of CIE whiteness, C/2° (indoor illumination conditions).
ISO 11475. Paper and board — Determination of CIE whiteness, D65/10° (outdoor daylight).
ISO 5631-2. Paper and board — Determination of colour by diffuse reflectance — Part 2: Outdoor daylight
conditions (D65/10°) .
ISO 5631-3. Paper and board — Determination of colour by diffuse reflectance — Part 3: Indoor illumination
conditions (D50/2°).
ISO 12647-1 to -8. Graphic technology – Process control for the production of half-tone colour separations, proofs
and production prints.
ISO TS 10128. Methods of adjustment of the colour reproduction of a printing system to match a set of
characterisation data.
ISO WD 15397 Graphic Technology — Communication of optical and surface properties of printing substrates. —
Graphic papers for rotogravure, heat-set web offset, offset sheets, proofing.
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