In the world of manufacturing, achieving a consistent surface finish is crucial. Gloss, a measure of a surface’s reflection, plays a key role in determining how shiny or matte a material appears. From gleaming car paint to the subtle sheen of a fine furniture finish, gloss directly impacts visual appeal and product quality. For manufacturers seeking to maintain precise gloss levels throughout production, reliable gloss meters are essential.
This buying guide explores the leading gloss measurement instruments, including the DeFelsko’s PosiTector® GLS series. BlastOne has a full range of inventory to help you find the perfect tool for your Quality Assurance and Quality Control (QA/QC) program.
Suitable for most gloss applications, preferred angle for semi-gloss
Suitable for high- to semi- gloss applications, calculates Haze (Haze Index)
Suitable for high-, semi-, and matte- gloss applications, calculates Haze (Haze Index)
Benefits
Most Affordable Option: Ideal for those who primarily measure semi-gloss finishes
Simple and Efficient: Well-suited for routine quality control checks
Wider Applicability: Measures at both 20° and 60° angles, suitable for high- to semi-gloss finishes
Haze Calculation: Calculates haze index, useful for evaluating surface clarity
Most Versatile: Measures at 20°, 60°, and 85° angles, ideal for all gloss levels (high, semi, matte)
Comprehensive Analysis: Calculates haze index for in-depth surface evaluation
Options
Standard Gauge/Body w/ Single Probe Kit
Advanced Gauge/Body w/ Single Probe Kit
Probe Kit Only (no gauge/body)
Standard Gauge/Body w/ Single Probe Kit
Advanced Gauge/Body w/ Single Probe Kit
Probe Kit Only (no gauge/body)
Standard Gauge/Body w/ Single Probe Kit
Advanced Gauge/Body w/ Single Probe Kit
Probe Kit Only (no gauge/body)
Gloss Meter Instrument Videos
How to Measure Gloss with the PosiTector GLS Gloss Meter
What is a Gloss?
Gloss is an optical property that indicates how well a surface reflects light in a specular (mirror-like direction)—how shiny or lustrous an object appears. On high gloss surfaces, light is reflected at the angle of incidence (specular reflection), but on matte surfaces, the reflected light is scattered (diffuse reflection).
Consumers love gloss—this can be seen in almost every industry from automotive, to electronics, to baby toys. No matter the industry, gloss tends to be associated with luxury and wealth. Studies suggest that humans’ innate love for glossiness could be based on the biological need for water: the glossier an object, the more likely to ‘quench thirst’.
From an industry standpoint, gloss can have a very specific purpose. By definition, gloss is an optical property that indicates how well a surface reflects light in a specular (mirror-like) direction—or, how lustrous or shiny an object appears. While many industries prefer a glossier finish, some require a more matte finish.
Why Measure Gloss?
Measuring gloss while a product is being manufactured can improve the production process by identifying process issues, maximizing consistency, reducing waste, and improving overall quality. Surface texture, coating properties, and paint application can all have an effect on a coating’s appearance. While it’s easy for the human eye to detect large differences in gloss, like comparing a matte finish on a military asset to a glossy red sports car, smaller differences in gloss can be harder to see—but can still have a big impact on process control.
What is Reflectance?
When light hits a surface, some of it is absorbed, and some is reflected. The reflected light is responsible for how the object is perceived. The nature of the reflection is generally related to the surface finish of the object. On a smooth, polished surface like a mirror, light is reflected opposite to the angle at which it arrives; this is referred to as ‘specular’ reflection. On a rough surface, light is reflected at all angles and a relatively small amount of light reflects at the specular angle.
What is Percent (%) Reflectance?
Reflectance is a measurement of the amount of light detected versus the amount of light sent and is expressed as a percentage. Gloss meters such as the PosiTector GLS can display in both GU and percent reflectance directly on the gage.
What is Gloss Value? What are Gloss Units?
Per ISO 2813, Gloss Value is a ratio of the reflectance of the test specimen to the reflectance of a standard polished black glass surface “with a refractive index of 1,567 at a wavelength of 587.6 nm in the specular direction”, multiplied by 100. It is expressed in terms of Gloss Units.
What is Haze Index?
Haze is the appearance of a “milky” halo or bloom perceived in reflective surfaces caused by microscopic imperfections in the surface’s texture. Haze Index is calculated and is defined by ASTM D4039 as the difference between gloss values measured at 60° and 20°. The PosiTector GLS 20/60 and 20/60/85 are capable of calculating haze when selected within the Setup menu.
How is Gloss Measured?
Digital gloss meters like the DeFelsko PosiTector GLS Gloss Meter measure the surface using a calibrated light source and light sensor at opposite, specular angles to each other. Reflectance is determined by comparing the amount of light energy emitted by the source with the amount of energy received by the sensor. Gloss is then automatically calculated using a look-up table.
The PosiTector GLS Gloss Meter includes a reference standard built into the base of the unit. When turning the unit on or when selected from the menu, the instrument automatically calibrates itself using the known Gloss Unit values of the standard.
Choosing the Best Angle for Gloss Measurement
On most surfaces, as the viewing angle increases, the reflectance and Gloss Value also increase. This is often apparent to the naked eye: for example, on the case below there is little apparent reflectance when viewed from above, but when that same case is viewed from a wider angle (nearer to the surface), visible reflectance can be seen. This phenomenon can be used to provide greater measurement resolution on high-gloss and matte finishes.
To determine the correct gloss measurement angle, gloss is first measured at a 60° angle:
If the result is between 10–70 GU, the object in question is considered semi-gloss and the 60° measurement angle is appropriate.
If the result is greater than 70 GU, the surface is considered high gloss and should be measured with the 20° angle.
If the result is less than 10 GU, the surface is considered matte and should be measured with the 85° angle.
How to take Gloss Readings with the PosiTector GLS Gloss Meter
PosiTector GLS 60° for measuring most gloss applications and is the preferred angle for semi-gloss
PosiTector GLS 20°/60° for measuring high-gloss to semi-gloss and calculating Haze Index
PosiTector GLS 20°/60°/85° for measuring high-, semi-, and matte gloss levels and also calculating Haze
Taking gloss measurements with the PosiTector GLS Gloss Meter is fast and easy:
1. It is critical that the calibration tile stays clean to verify the accuracy of the meter. Periodically, or when dirt or debris is visible, the gloss standard should be cleaned using the included cleaning wipes. Once the self-check is successful, the PosiTector GLS is ready to measure.
2. Before powering the gage on, ensure that the protective base plate is securely on the probe. When powered on and with Power-On Cal enabled, the probe will automatically perform a self-check and calibration using the calibration standard incorporated into the protective base plate; traceable certificates of calibration are included for both the probe and the gloss standard.
3. Remove the protective base plate from the probe and place the probe on a firm, flat surface. Simply press the button to take a reading; the gage will beep twice and a measurement will be displayed.
Features of the PosiTector GLS Gloss Meter
The PosiTector GLS boasts multiple measurement modes and helpful features that make it suitable for nearly any application:
HiLo mode: for quick inspection or pass/fail checks
Differential Mode: automatically calculates the difference between current reading and stored reference value*
Normal Scan Mode: measure and save up to 120 readings per minute*
Statistics Scan Mode: continuously measures and displays real-time statistics, saving each scan into memory*
Alternate Calibration Standards: store multiple calibration standards (tiles) for quick calibration adjustment
*Available on PosiTector GLS Advanced models only
Since it is part of the PosiTector platform, the PosiTector GLS is compatible with any PosiTector probe; quickly converting from a gloss meter to a coating thickness gage, surface profile gage, environmental meter, and more. It also has the added benefit of a large 2.8” impact resistant color touchscreen, and an easy-to-use menu. Advanced gage bodies can connect to personal smart devices or laptops via WiFi or Bluetooth.
Manage Gloss Measurement Data with PosiSoft Software
When gloss inspection is complete, download the readings using the built-in USB port, or via WiFi if using an Advanced gage body. When connected, download, view, and print stored readings in professional PDF reports quickly and easily with PosiSoft Desktop software. Fully customized reports can be created to match existing paper forms or layouts.
Conclusion
While gloss measurement is often done for aesthetic reasons, measuring gloss can have a big impact on process and quality control. The PosiTector GLS Gloss Meter comes fully featured to handle many gloss measurement applications. Watch the video below or view the product page for more information.
What is Reflectance?
Reflectance is the measurement of the amount of light detected versus the amount of light emitted and is expressed as a percentage. Some light waves are absorbed into the coating while others are reflected. The amount of light reflected is used to calculate gloss.
Some gloss meters, like the PosiTector GLS Gloss Meter can display both Gloss Units and Percent Reflectance (% Reflectance).
What is Haze?
Haze is the appearance of a milky halo or bloom perceived in reflective surfaces due to microscopic imperfections in the coatings surface. The reflection from high gloss surfaces should be crisp but surface imperfections will tend to scatter the light producing a hazy appearance.
Gloss meters such as the PosiTector GLS 20°/60° and GLS 20°/60°/85° can calculate Haze Index in accordance with ASTM D4039 by subtracting the 20° from the 60° specular gloss measurements.
How is Gloss Measured?
Gloss, Percent Reflectance, and Haze are measured using a digital gloss meter like the PosiTector GLS. The meter uses a calibrated light source and a light sensor at opposite, specular angles. Percent Reflectance is measured by comparing the amount of light sent versus the amount of light received. Gloss is then calculated automatically.
Which Gloss Meter is Right for My Application?
Selecting the Right Measurement Angle for Gloss
The 60° angle is often the starting point for selecting the appropriate gloss measurement geometry. This initial reading helps determine the ideal angle for your specific application:
High Gloss (above 70 Gloss Units (GU) at 60°): Surfaces exceeding 70 GU at 60° are considered high-gloss and are best measured using a 20° angle. These finishes are commonly found on cars and other consumer goods, where a mirror-like shine is desired.
Matte (below 10 GU at 60°): Finishes reading less than 10 GU at 60° fall into the matte category. An 85° angle is recommended for accurate measurement of these surfaces. Matte finishes are often used on fabrics, leathers, and military equipment for their low-glare properties.
Semi-Gloss (between 10 and 70 GU at 60°): If the 60° measurement lands between 10 and 70 GU, the surface is considered semi-gloss. In this case, the 60° angle is perfectly suitable for capturing the gloss characteristics.
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ASTM C584—Standard Test Method for Specular Gloss of Glazed Ceramic Whitewares and Related Products
This test method covers the determination of 60° specular gloss of glazed ceramic whitewares and related products.
Refer to ASTM C584 for a complete description of the test method
ASTM D523—Standard Test Method for Specular Gloss
This test method covers the measurement of specular gloss of nonmetallic specimens for gloss meter geometries of 20°, 60°, and 85°.
Refer to ASTM D523 for a complete description of the test method
ASTM D4039—Standard Test Method for Reflection Haze of High-Gloss Surfaces
The test method describes a procedure for using two specular gloss measurements to obtain a haze index for high-gloss nonmetallic specimens. It is particularly useful for evaluating the haze in clear finishes on nonglossy substrates, and the haze in reflected images produced by the surfaces of opaque glossy pigmented surfaces.
Refer to ASTM D4039 for a complete description of the test method
ISO 2813—Paints and Varnishes—Determination of gloss value at 20°, 60°, and 85°
This International Standard specifies a method for determining the gloss of coatings using 20°, 60°, and 85° geometries. The method is suitable for the gloss measurement of non-textured coatings on plane, opaque substrates.
Refer to ISO 2813 for a complete description of the test method
ISO 7668—Anodizing of aluminum and its alloys—Measurement of specular reflectance and specular gloss of anodic oxidation coatings at angles of 20°, 45°, 60°, or 85°
This International Standard specifies methods for measurement of specular reflectance and specular gloss of flat samples of anodized aluminum using geometries of 20° (Method A), 45° (Method B), 60° (Method C), and 85° (Method D); and of specular reflectance by an additional 45° method (Method E) employing a narrow acceptance angle. The methods described are intended mainly for use with clear anodized surfaces. They can be used with colour-anodized aluminum, but only with similar colours.
Refer to ISO 7668 for a complete description of the test method
DIN 67530—German Institute for Standardization (Deutsches Institut für Normung—DIN) Paints and Varnishes—Determination of gloss value at 20°, 60°, and 85°
International Standard for using a reflectometer to assess the specular gloss properties of smooth-painted and plastic surfaces. (This standard has been replaced by ISO 2813.)
Refer to DIN 67530 for a complete description of the test method
JIS Z 8741—Specular Glossiness—Methods of Measurement
This Japanese Industrial Standard specifies the methods of measurement for specular glossiness of the macroscopically smooth surface of product of mining and manufacturing industry.
Refer to JIS Z 8741 for a complete description of the test method
AS/NZS 1580.602.2—Paints and Related Materials—Method of Test—Measurement of Specular Gloss of Non-Metallic Paint Films at 20° degrees, 60° degrees, and 85° degrees
This International Standard is one of a series of standards dealing with the sampling and testing of paints, varnishes, and related products. It specifies a test method for determining the specular gloss of paint films using a reflectometer geometry of 20°, 60°, 85°. The method is not suitable for the measurement of the gloss of metallic paints. Identical to, and reproduced from, ISO 2813.
Refer to AS/NZS 1580.602.2 for a complete description of the test method
Frequently Asked Questions
What is gloss and why is it important to measure?
Gloss is an optical property that indicates how well a surface reflects light in a specular (mirror-like) direction. It refers to how lustrous or shiny an object appears, generally affecting its aesthetic and perceived value.
Gloss measurement is useful for identifying process issues and defective parts—maximizing consistency, reducing waste, and improving quality.
What is Reflectance?
When light hits a surface, some of it is absorbed, and some is reflected. The reflected light is responsible for how the object is perceived. Reflectance as it relates to gloss measurement is the proportion of light sent and the amount of light detected.
What is a Gloss Unit (G.U.)?
Gloss Units are the unit of measurement typically measured and reported when measuring gloss. Gloss Units are defined by standards such as ISO 2813. Gloss meters such as the PosiTector GLS can display in both GU and percent reflectance directly on the gage.
What is Haze?
Haze in relation to gloss measurement is the appearance of a “milky” halo or bloom perceived in reflective surfaces.
Does the PosiTector GLS need to be 'calibrated' or 'adjusted' prior to use?
The innovative technology and factory calibration in the PosiTector GLS means that it arrives ready-to-measure—usually there is no need to perform a calibration adjustment. If the probe is resting in the included protective base plate and the Power-On Cal feature is enabled, the probe will automatically perform a check and calibration using the certified gloss standard (tile) incorporated in the base plate.
Does the PosiTector GLS require any formal training for use? Do you offer 'demo' models?
No. The PosiTector GLS is designed for simple operation, featuring easy-to-use menus, instruction manuals, and helpful videos. In lieu of demonstration models, we provide unlimited technical support via telephone and/or email, and a limited 30-day money back guarantee. Watch the PosiTector GLS video to see the gloss meter in action.
How often should the PosiTector GLS be recalibrated?
PosiTector GLS Gloss Meters include a Certificate of Calibration with no expiry or end date. Many organizations with a quality program and recertification programs require annual recalibrations, and this is a good starting point for most users. DeFelsko recommends that customers establish calibration intervals based upon their own experience and work environment. Based on our product knowledge, data and customer feedback, a one-year calibration interval from the date the instrument was placed in service is a good starting point.
What is the measurement range of the PosiTector GLS Gloss Meter?
PosiTector GLS Gloss Meters are available in three different models:
PosiTector GLS 60° — Suitable for most gloss applications (0–1000 GU)—preferred angle for semi-gloss.
PosiTector GLS 20° / 60° — Ideal for high- to semi-gloss surfaces (0–2000 GU)—also capable of calculating Haze Index.
PosiTector GLS 20° / 60° / 85° — Suitable for all gloss applications including high-, semi-, and matte-gloss—also capable of calculating Haze Index.
How many readings can the PosiTector GLS Gloss Meter store into memory?
The PosiTector GLSStandard is capable of storing up to 1,000 readings into memory. The PosiTector GLS Advanced can store up to 250,000 readings in 1,000 batches. Both Standard and Advanced models feature a USB port and include a USB cable to download, view, and print stored readings quickly and easily with PosiSoft Desktop.
How fast can the PosiTector GLS Gloss Meter measure?
By default, PosiTector GLS Gloss Meter Standard models can take 60+ readings per minute. With an Advanced PosiTector gage body, 2 powerful scan modes (Normal and Statistics) allow for even faster and more efficient measurements.
What is the HiLo Alarm Mode for the PosiTector GLS?
Available on both PosiTector GLS Standard and Advanced models, HiLo Alarm Mode audibly and visibly alerts when measurements exceed user-specified limits, and can be used as Pass/Fail for quick inspection. View the following video for an example of how HiLo Alarm Mode works.
What is the Normal Scan Mode for the PosiTector GLS?
The PosiTector GLS Advanced features a “Normal Scan Mode” for making short work of measuring gloss over large surfaces. View the video for an example of how Normal Scan Mode works.
What is the Statistics Scan Mode for the PosiTector GLS?
The PosiTector GLS Advanced features a “Statistics Scan Mode” for measuring gloss levels. Take continuous readings and record average, standard deviation, min/max, and number of readings while scanning. View the video for an example of how Statistics Scan Mode works:
What Standards does the PosiTector GLS Gloss Meter conform to?
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