The official current version is ASTM D523-14 (Reapproved 2018)
, though a 2025 revision is scheduled for release soon. This standard is the primary global benchmark for measuring the specular gloss
of non-metallic materials like paints, plastics, and coatings. Quick Reference: The Three Geometries
The choice of measurement angle depends on the initial shininess of your sample: 60° (Universal)
: Used for most samples. If the result is between 10 and 70 Gloss Units (GU), stick with this angle. 20° (High Gloss) : Used if the 60° reading is above 70 GU . It provides better resolution for very shiny surfaces. 85° (Low Gloss/Matte) : Used if the 60° reading is below 10 GU
. This "grazing angle" is more sensitive to differences in matte finishes. 🛠️ Step-by-Step Testing Guide 1. Equipment Setup
Understanding ASTM D523: The New Standard for Specular Gloss Measurement
ASTM D523 is the globally recognized standard test method for measuring the specular gloss of nonmetallic specimens. Whether you are in automotive, plastics, or coatings, understanding this standard is essential for ensuring product quality and aesthetic consistency. What is ASTM D523? astm d523 pdf new
This test method provides a quantitative way to measure how "shiny" or reflective a surface is. By using a calibrated glossmeter, manufacturers can assign a numerical value—recorded in Gloss Units (GU)—to a surface's reflective capacity. The Latest Update: ASTM D523-25
The newest iteration of this standard is ASTM D523-25, released in June 2025. It supersedes the long-standing D523-14(2018) version.
For professionals requiring the most current data, you can purchase the active standard and its accompanying "Redline" version (which highlights specific changes between versions) directly from the ASTM International Store. Key Measurement Geometries
ASTM D523 specifies three primary angles of reflection, each suited for different gloss levels: D523 Standard Test Method for Specular Gloss - ASTM
standard, titled "Standard Test Method for Specular Gloss," is the primary international guideline for measuring the visual shininess of nonmetallic materials. The current active version is ASTM D523-14(2018)
, which was reapproved in 2018 to ensure its continued technical relevance. ASTM International Core Measurement Geometries
The standard utilizes three specific angles (geometries) to categorize the gloss level of a surface: 60° (Universal) The official current version is ASTM D523-14 (Reapproved
: Used for most specimens. It acts as the starting point to determine if a more specialized angle is needed. 20° (High Gloss)
: Applied when the 60° reading is higher than 70 units. It provides better resolution for very shiny surfaces. 85° (Matte/Low Gloss)
: Applied when the 60° reading is lower than 10 units. This "grazing angle" is more sensitive to differences in low-gloss surfaces. Valspar Industrial Mix Technical Application : Measurements are performed using a glossmeter
, which compares the light reflected from a specimen against a standard (typically highly polished black glass).
: While widely used for paints and coatings, it is applicable to various nonmetallic solids like plastics, ceramics, and wood finishes. Calibration
: Accurate results require frequent calibration using primary or secondary reference standards to maintain the 20, 60, and 85-degree scales. Valspar Industrial Mix D523 Standard Test Method for Specular Gloss - ASTM
The ASTM D523 standard is the primary method for measuring the specular gloss of nonmetallic specimens using three specific light-reflectance angles: 20°, 60°, and 85°. It is widely used in industries like coatings, plastics, and manufacturing to ensure visual consistency and surface quality. Core Content Outline for ASTM D523 ASTM D523: Specular Gloss Test Method | PDF - Scribd Obsolete Versions: Most free sites host D523-14 (2014)
The new procedure explicitly warns against measuring through protective film or glass. It also adds a mandatory check for "drift" after every 10 measurements.
It is tempting to look for a free PDF. A quick Google search yields dozens of sites offering "ASTM D523 PDF free download." Do not use them. Here is why:
When you search for "astm d523 pdf new", you are not just looking for a file—you are looking for authority and accuracy.
Searching for "astm d523 pdf new" implies you already know that older versions are problematic. Here is why the newest revision is essential:
The new version explicitly excludes curved surfaces (which require a different standard, ASTM E430) and clarifies that it is not for use with metallic or mirror-like surfaces due to secondary reflections.
Modern materials (water-borne coatings, UV-cured plastics) require specific temperature (23±2°C) and relative humidity (50±5%) conditioning times. The new PDF specifies 24 hours minimum unless otherwise agreed.
The latest standard adds definitions for terms like "specular reflectance factor" and clarifies the difference between "gloss units" (GU) and percent reflectance.