Record the L*a*b values of the sample and the reference with a calibrated spectrophotometer or colorimeter. Compute the difference in the color by use of ΔE. The lower the Delta E, the more accurate the result. The difference in energy, ΔE < 1, is generally assumed to be invisible to the eye.

SCI&SCE are two method in the color measurement. SCI means Specular Component Include,SCE means Specular Component Exclude.

Under the method of SCE, only test diffuse refection and exclude specular reflection. In that way, the test result is similar to object color was observed by human eyes.

Under the method SCI, both the diffuse refection and specular reflection will be included. In that way, the value about the color is more objective. It will not effect by the environment condition.

When we choose the instrument, those elements should be taking into consideration.

Colors look different under various lights mainly because of metamerism—a phenomenon where two colors that match under one light source fail to match under another, caused by differences in the spectral composition of light.

Different lighting varies the color perception of objects. Warm light, like that from incandescent bulbs, tends to make colors more yellow, while daylight presents a bluish tint. Our color vision system plays a compensating role using a mechanism called color constancy.

Every light source emits light with a unique "spectral fingerprint" (i.e., the range and intensity of wavelengths it contains). This directly affects how an object’s surface reflects light and how our eyes perceive its color.

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

In industrial production and quality control, color consistency is one of the core elements determining product quality. Whether it is the metallic paint for automobile coating, the dyeing effect of textile fabrics, or the ink matching in packaging and printing, subtle color deviations may lead to cost waste or damage to brand image.

The LAB color space defines colors with a three-dimensional model:

1. Lightness (L): It indicates the lightness or darkness of a color, ranging from 0 (pure black) to 100 (pure white).

2. Hue and Saturation (a and b):

• The a-axis represents the red-green tendency, with positive values leaning towards red and negative values leaning towards green;

• The b-axis represents the yellow-blue tendency, with positive values leaning towards yellow and negative values leaning towards blue.

It is a globally recognized standard and supported by most modern color measurement equipment. Color is quantitatively analyzed by measuring Lab values with instruments.

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. 

The gloss meter is used to measure gloss at typical angles (typically 20°, 60°, or 85°). The instrument illuminates the material and measures the amount of light reflected and states the outcome in gloss units (GU), which is related to perceived brilliance.

Usually you will find haze and transmittance standards of ASTM D1003, ISO 13468, & JIS K7105.

A spectrophotometer measures the full visible color spectrum (typically 400–700 nm). It offers significantly higher precision and enables detailed evaluations – including spectral curves, ΔE values, and color distance measurements. It is the preferred choice for demanding applications in labs or color development environments. learn more..

The core difference between a colorimeter and a spectrophotometer lies in their light measurement methods. A colorimeter measures color values based on the tristimulus method (e.g. LAB or RGB) and compares the sample to a reference. It's ideal for quick, repeatable measurements under consistent conditions – such as in production or incoming goods control.

Once ignited, the gauge will select the correct substrate mode. The probe should be placed flat on the coated surface. The thickness of the coating will show on the screen. Measurements should be taken on different areas of the surface to ensure accuracy.