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White Paper
GLOSS STANDARDS & MEASUREMENT
What is Gloss?
Gloss is defined as the degree to which a surface exhibits
specular reflectance. This means that it is a measure of
the image forming ability of a surface. In the case of glass
or plastic sheets used for display enhancement, gloss is of
interest because surface treatments known as antiglare
treatments create a low gloss surface. In order to accurately specify and repeatably manufacture antiglare filters, it is necessary to understand how low gloss is
obtained, how it is specified and controlled and how it is
measured. This white paper will consider all of these
aspects.
eral, the gloss is first measured with the 60° geometry.
The value obtained is reported if it is between 10 and 70
units. If the gloss reading is higher than 70, it is recommended that a measurement be taken at 20°, while the
85° geometry is used for readings below 10 (30 in the DIN
standard). The use of different angles is needed because
of the differences in measurement response at the different angles.
The Impact of Gloss on Displays
Low gloss will affect a display in two ways; first, a low
gloss surface will reduce or eliminate the “white shirt”
effect and second, the information content of the display
will appear to have a blurry and perhaps speckled appearance. The “white shirt” effect is reduced because the light
is diffusely reflected from the display surface, which minimizes the amount of specular reflections (see the Reflections on Reflections white paper for a more complete
description). At the same time, however, the light from
the display is also diffused by the low gloss surface. If the
etching is relatively coarse, the light from the display will
be focussed by the surface structure of the low gloss surface, resulting in an appearance in which the apparent
brightness of a pixel will vary from point to point and
over varying view angles. The degree of this diffusion and
speckling is strongly influenced both by the distance
between the emitting surface of the display and the diffusing surface and the degree of etch. It is the task of the
display designer and manufacturer to arrive at the best
compromise of reduced reflections and impaired
appearance.
What Affects Gloss?
The perception of gloss is influenced by numerous factors, among them being: material being used, surface profile (structure and shape), transparency of the material.
Polished glass and plastic, made by reliable manufacturers, will generally exhibit very high gloss numbers. Panels
with additives designed to create a more or less milky
appearance will exhibit low gloss values, as will those
with surface etches. Gloss perception is also affected by
details of the nature of the light source(s) and the observer’s physical and emotional states. Gloss evaluation
requires a direct source of illumination. A diffuse source
causes a decreased gloss impression. Because the perception of gloss is not simply a physical measurement, it is
often difficult to describe adequately. The paint and surface finish industries have developed several standards
for defining gloss and how to measure it. The most important specifications include:
For More Information
Determining the best solution for your particular application can be a daunting task. We invite you to visit our
web site, http://www.GDOptiLabs.com, for the latest
information available on LCD, OLED and Plasma display
optical enhancements. Or call 800.952.2535 to speak
with a Sales Engineer.
• ISO 2813
• ASTM D 523
• DIN 67530
Page 1 of 1
Measuring Gloss
Several manufacturers produce gloss meters, such as
BYK-Gardner, from whom most of this information has
been derived. In order to assure reproducible data is
obtained, it is necessary to standardize the instruments:
Angle of illumination and regard are specified at angles of
20°, 60° and 85°. Dimensions of the source and receptor,
light source (spectral characteristics) and sensitivity of
the receptor are all specified and held constant within a
given instrument. The theoretical standard for comparison is a highly polished black glass with a refractive index
of 1.567, which is assigned a gloss value of 100 for each
geometry. Several practical standards have been proposed
and at least two versions are readily available. Measurement error should typically not exceed ±1 unit. In gen-
General Digital ™ Optical Bonding Laboratories 8 Nutmeg Road South South Windsor, CT 06074 Toll-Free: 800.952.2535
Local: (860) 282-2900
Fax: (860) 282-2244
E-mail: [email protected]
Web: www.GDOptiLabs.com




Specifications subject to change without notice or obligation. Trademarks are the property of their respective owners.


February 2007