ASTM D4449-90(2004)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D 4449 – 90 (Reapproved 2004)
Standard Test Method for
Visual Evaluation of Gloss Differences Between Surfaces of
Similar Appearance
This standard is issued under the fixed designation D 4449; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2.3 gloss, of a surface, n—perceived directionally selec-
tive reflecting properties responsible for the degree to which
1.1 This test method covers the visual evaluation of gloss
reflected highlights or images of objects may be seen as
differencesofcoatingsurfaces,usingspecialtypesoflampsfor
superimposed on the surface.
illumination. It identifies six aspects or types of gloss that one
3.2.4 reflection haze, n—cloudy or milky appearance of a
may look for when using the lamp to assess gloss differences
surfaceadjacenttodirectionsofspecularreflection(seeFig.3).
between surfaces. It describes the conditions for using the
3.2.5 sheen, n—perceived shininess at a near-grazing angle
lamps to best identify small differences in each of the six types
of incidence for an otherwise matte specimen (difficult to
of gloss. Four levels of visual gloss differences are distin-
photograph).
guished.
3.2.6 specular gloss, n—the relative luminous reflectance
1.2 While this technique is useful for both weathered and
factor of a specimen in the specular direction. The luminous
unweathered specimens, it has not been applied to metallics.
reflectance factor is the ratio of the luminous flux reflected
1.3 The values stated in SI units are to be regarded as the
from, to that incident on, a specimen for specified solid angles
standard. The values given in parentheses are for information
(see Fig. 4).
only.
3.2.7 texture, n—perceived structure, pattern, or topography
1.4 This standard does not purport to address all of the
or combination thereof, of a surface (see Fig. 5).
safety concerns, if any, associated with its use. It is the
responsibility of whoever uses this standard to consult and
4. Summary of Test Method
establish appropriate safety and health practices and deter-
4.1 Test specimens are illuminated by special light sources
mine the applicability of regulatory limitations prior to use.
that provide reflected images suitable for rating the gloss of
2. Referenced Documents coating surfaces. Two types of lamps may be used to produce
reflected images. Lamp A consists of a modified fluorescent
2.1 ASTM Standards:
desk lamp covered with screen mesh. Lamp B consists of an
D 3964 Practice for Selection of Coating Specimens for
incandescent bare filament bulb installed in an adjustable angle
Appearance Measurements
fixture.
E 284 Terminology of Appearance
4.2 Light from the selected lamp illuminates the test speci-
3. Terminology
mens.The reflected images reveal specular gloss reflection; the
sharpness of the images of the screen or lamp filament reveals
3.1 Definitions:Fordefinitionsoftermsusedinthismethod,
the detail and quality of the surface reflection (distinctness of
see Terminology E 284.
image); and spreading of the reflected light into dark areas,
3.2 Descriptions of Terms Specific to This Standard:
suchasthespacebetweenfluorescenttubesornearthefilament
3.2.1 directionality of surface, n—perceived change of
image, reveals the presence of near-specular haze.
glossyappearanceofasurfacewithrotationofthesurfaceinits
own plane (see Fig. 1).
5. Significance and Use
3.2.2 gloss, distinctness-of-image, n—perceived sharpness
5.1 Gloss is associated with the capacity of a surface to
of images reflected by an object surface (see Fig. 2).
reflect more light in some directions than in others. The
directions associated with mirror (or specular) reflection nor-
This test method is under the jurisdiction of ASTM Committee E12 on Color
mally have the highest reflectances. Gloss is best seen and
and Appearance and is the direct responsibility of Subcommittee E12.11 on Visual
Methods. analyzed when the surfaces studied are illuminated by a light
Current edition approved Nov. 1, 2004. Published November 2004. Originally
approved in 1985. Last previous edition approved in 1999 as D 4449 – 90 (1999).
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 For a more detailed account of gloss, its measurement, and relationship to
Standards volume information, refer to the standard’s Document Summary page on appearance generally, see R. S. Hunter, The Measurement of Appearance, Wiley
the ASTM website. Interscience New York, NY 1975.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 4449 – 90 (2004)
NOTE 1—The left panel is free of directionality. The right panel is highly directional because of buffing marks.
FIG. 1 Reflection of Bright Incandescent Lamp in Two Panels
NOTE 1—The panels exhibit a difference in distinctness-of-reflected image.
FIG. 2 Two White Porcelain Enamel Panels
source that provides strong contrasting patterns of light and materials) highly variable and affected by a variety of factors:
dark. Such a light source is described in this test method. surface smoothness and contour, refractive index, absorptance,
5.2 The simplest concept of gloss is that it corresponds to angle of incidence, and (to a generally small extent) wave-
the mirror-like reflectances of surfaces. However, the distribu- length.Fromthegreatvarietyofsurface-reflectionpatternsmet
tions and intensities of this surface-reflected light are (for real inmaterialsofcommerce,ithasbeenpossibletoidentifyseven
D 4449 – 90 (2004)
FIG. 3 Two Blue Plastic Wall Tiles Exhibiting a Difference in Reflection Haze
6.2 Lamp B—The recommended apparatus is an incandes-
cent bare filament bul
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