The Difference in Application of SCI and SCE in Colour Measurement

Introduction

Colour measurement is a process that must be carried out accurately to guarantee consistent and reliable results, especially in industries such as automotive, textiles, and paint. Two important methods used in spectrophotometric colour measurement are Specular Component Included (SCI) and Specular Component Excluded (SCE). These techniques play a crucial role in how colours are analysed and assessed, depending on the nature of the surface and the intended application. It is essential to understand when and why each method is used in order to obtain the most accurate colour measurements.

What is SCI (Specular Component Included)?

The SCI method measures the total amount of light reflected by a surface, including both the diffuse and specular (glossy) reflection. This means that both the light scattered in all directions (diffuse reflection) and the light reflected directly back (specular reflection) are included in the measurement. This results in a measurement that is independent of the surface condition, meaning the colour value remains constant regardless of whether the surface is glossy or matte.

Application: SCI is often used in laboratories and when developing colour formulas, where an exact colour match is required without the influence of gloss. It is useful for determining the “true” colour of a material, regardless of the surface finish. This is of great importance when formulating colours for products such as automotive paint, where colour accuracy is crucial.