D/8°and 45°/0°are two kinds of illumination geometry with different optical geometry design. D/8°illumination geometry is more widely used for the color comparison and measurement of high-gloss materials; 45°/0°illumination geometry is mainly used in printing and packaging industries. 

Readings of gloss meters in gloss units (GU) are used to measure shine on the surface. Low GU (0-10) is matte, 10-70 semi-gloss or satin, and above 70 is glossy. Measurement angle is given to the readings: 60° is the normal, 20° is the high gloss, and 85° is the low gloss.

The principle of colorimetry is the law of Beer-Lambert, which says that the intensity of light absorbed by a colored solution is proportional to the concentration of the absorbing species and the path length. It measures the extent of light that is absorbed at certain wavelengths.

A colorimeter sends light through a solution and measures the amount that is absorbed. It computes the absorbance by comparing the intensity of light before and after passing through. The greater the concentration of the color, the greater is the absorption of the light. It is also possible to quantify the color of the solution.

Take L*a*b* readings of two samples using a colorimeter or spectrophotometer and calculate color difference using the 3 formula (Delta E). The difference in 0 is the reported Delta-E, which shows how visible the change is, whereas the thresholds define the acceptability as per the application requirements.

A colorimeter is sufficient when measuring similar materials or batches with stable conditions. Suitable for fast, low-cost color checks where high precision is not required. Quick quality control in plastics, paint batch consistency, food color grading (e.g., fruit ripeness), and basic printing checks.

A spectrophotometer is recommended when you need professional, maximum color accuracy or when testing materials with variable surfaces – such as glossy or textured samples. Like textile dye formulation, cosmetic shade matching, medical device color calibration, high-end printing (e.g., packaging for luxury goods), and material spectral research. learn more Understanding Spectrophotometric Parameter Measurement

The most important equation is A = 2εcl, where A is the absorbance, 2 is a constant, ε is the molar absorptivity (L/mol cm), c is the concentration (molL-11), and l is the path length (cm). This can be used to relate the absorbance to the concentration, allowing quantification through colorimetric assays.

Common sources like D65, TL84, and CWF mimic daylight, store, home, and fluorescent lighting, and are used to provide conditions for dependable color comparison.

Powder paint gloss levels are commonly classified as:

● Flat/Matte: 0–10 GU

● Satin: 10–40 GU

● Semi-Gloss: 40–70 GU

● Gloss: 70–85 GU

High Gloss: 85+ GU
These ranges can vary by manufacturer and application angle.

The Ideal Accurate and User - Friendly Spectrophotometer for Your Needs 

This Spectrophotometer device measures the reflectivity，absorbance, transmittance, and fluorescence of light passing through samples, providing invaluable data for a wide range of applications, provide unrivaled accuracy for reliable results. 

Selecting an appropriate spectrophotometer offers significant advantages for precision color analysis and quality control. When choosing an accurate and user - friendly spectrophotometer, consider factors such as wavelength range, sensitivity, sample handling options, and available software features. By investing in the right spectrophotometer, you can streamline your analytical processes, obtain more accurate results, and enhance the overall efficiency of your laboratory or industrial operations. 

 Choosing the right model—whether portable, benchtop, or inline—aligns technology with specific industry needs, ensuring long-term reliability and optimized color management.