ASTM D7305-08a(2020)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D7305 −08a (Reapproved 2020)
Standard Test Method for
Reflection Density of Printed Matter
This standard is issued under the fixed designation D7305; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope E691Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
1.1 This test method describes a procedure for measuring
2.2 ANSI Standards:
reflectiondensityofprintedmatterusingareflectiondensitom-
CGATS.4-1993Graphic Technology – GraphicArts Reflec-
eter or spectrodensitometer.
tion Densitometry Measurements — Terminology,
1.2 Thistestmethodisintendedprimarilyforprocesscolors
Equations, Image Elements and Procedures
(yellow, magenta and cyan) and black. With appropriate
CGATS.6GraphicTechnology—SpecificationsforGraphic
instrumentation, it may also be used for other colors.
Arts Printing
1.3 This test method applies to prints made by any printing
CGATS.11-1999Graphic Technology — Certified Refer-
processonaflatsurface,withreflectiondensityvaluesranging
enceMaterialsforReflectionandTransmissionMetrology
from just above zero, on the unprinted substrate, through to
– Documentation Requirements and Recommended Pro-
around 2.5 for very dense prints.
cedures
PH 2.17Geometric Conditions for Reflection Density
1.4 Thistestmethodcanbeusedforprintsonpaper,filmor
PH2.18SpectralConditionsfortheMeasurementofOptical
board but not for those on metal or foil. It can be conducted in
Density
the pressroom or laboratory.
2.3 ISO Standard:
1.5 The values stated in SI units are to be regarded as
ISO 15790Graphic technology and photography — Certi-
standard. No other units of measurement are included in this
fied reference materials for reflection and transmission
standard.
metrology — Documentation and procedures for use,
1.6 This standard does not purport to address all of the
including determination of combined standard uncertainty
safety concerns, if any, associated with its use. It is the
2.4 Other Standard:
responsibility of the user of this standard to establish appro-
DIN 16536-2:1986Testing of prints and printing inks in
priate safety, health, and environmental practices and deter-
graphic technology — Colour density measurements on
mine the applicability of regulatory limitations prior to use.
on-press or off-press prints
1.7 This international standard was developed in accor-
dance with internationally recognized principles on standard-
3. Terminology
ization established in the Decision on Principles for the
3.1 Definitions related to appearance are in Terminology
Development of International Standards, Guides and Recom-
E284.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 reflection density, n—the light-absorbing property of a
2. Referenced Documents
material, expressed as the logarithm of the reciprocal of the
reflectance factor (i.e. higher density indicates more light is
2.1 ASTM Standards:
absorbed). [D = log (1/R) = -log (R)]
E284Terminology of Appearance 10 10
3.2.2 reflection densitometry, n—the practice of characteriz-
ing the amount of light absorption of materials by measuring
This test method is under the jurisdiction of ASTM Committee D01 on Paint
reflectance and calculating and reporting reflection density.
and Related Coatings, Materials, andApplications and is the direct responsibility of
3.2.3 spectrodensitometer, n—a spectrophotometer with ap-
Subcommittee D01.56 on Printing Inks.
CurrenteditionapprovedJune1,2020.PublishedJuly2020.Originallyapproved propriate software to convert the measured reflectance values
in 2008. Last previous edition approved in 2013 as D7305–08a (2013). DOI:
to reflection density.
10.1520/D7305-08AR20.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7305 − 08a (2020)
chromatic inks at typical printing densities.
3.2.4 process color, n—a color having the main attribute of
absorbing approximately one-third (1/3) the visible spectrum
4. Symbols
and transmitting the other two-thirds (2/3).
4.1 Symbols—The following symbols are defined or re-
3.2.5 dry back, n—the reduction in density that occurs over
ferred to in this standard.
time after printing on paper and other absorbent substrates due
D reflection density
to ink penetration into the substrate.
R reflectance factor
3.2.6 status T, n—an ISO Reflection Status Density.
5. Summary of Test Method
NOTE 1—ISO Reflection Status Density is defined by its Spectral
Products (Fig. 1), that is, the wavelength by wavelength combination of a
5.1 The densitometer or spectrodensitometer is calibrated
standard influx spectrum (CIE illuminantA) and the filter-modifed efflux
and set for the desired spectral response and color.
spectrum. Originally, these modifiers were defined by combinations of
Wratten filters but today, either more durable materials, such as glass are 5.2 Multiple reflection density measurements are taken in
used or the Spectral Products are computed numerically from tables of
specifiedpositionsontheprintinordertodetermineanaverage
weights and the spectral reflectance factors measured with a spectroden-
result.
sitometer.
The status T spectral products are applicable to the measurement of
6. Significance and Use
artwork for color separation and graphics arts materials such as ink-on-
paper printed sheets, and off-press proofs. StatusTwas originally defined
6.1 One of the key properties for printing in the lab or on
to closely match the spectral products historically used in evaluating
production equipment is the intensity of the color, color
originalartworktobecolorseparatedbutwerelaterapplied,notablyinthe
balanceanduniformity.Thistestcanbeusedtoensurethatthe
USA, to the measurement of most other printed graphic arts materials.
proper amount of ink is transferred to the substrate by
The status E spectral products are also applicable to the measurement
obtaining a target density value, in addition to determining
of graphics arts materials such as ink-on-paper printed sheets, and
off-press proofs. They evolved from the wider of the two passband filter
whether the print is uniform by measuring the reflection
specifications of DIN 16536-2:1986 for the Yellow and the Magenta and
density over a wide print area. This then allows the use of the
Cyan spectral products were chosen to match those of Status T. Status E
printforcontrolledtestingofotherappearanceproperties,such
spectral products have been applied, primarily in Europe, to the measure-
as gloss and color, and performance properties, such as
ment of graphic arts materials.The narrower passband of theYellow filter
(compared to Status T) produces values that are more similar for all three resistance to abrasion and chemicals.
FIG. 1 ISO Status Density Spectral Products
D7305 − 08a (2020)
6.2 This test can be used to help achieve consistent color T-Ref standard. Readings that differ from the labelled value on
reproduction of printed color on flat surfaces. thecertifiedreferencematerialbymorethanthegreaterof0.02
density units or 2% should be discussed with the densitometer
6.3 Transfer of density readings from one set of inks to
manufacturer in order to determine whether the particul
...