Colorimetry

What Is Colorimetry?

Colorimetry measures color under controlled conditions and reports results as standardized values. Unlike visual inspection, which varies by lighting and observer, colorimetry provides repeatable, objective data that can be used for specifications, acceptance criteria, and process control.

Colorimetry is widely used for materials, coatings, plastics, textiles, packaging, consumer products, and pigments—any product where appearance matters.

What Colorimetry Measures

Typical outputs include:

CIELAB L*a*b*
- L* = lightness (0 = black, 100 = white)
- a* = green (−) to red (+)
- b* = blue (−) to yellow (+)
ΔE (color difference)
Quantifies how different two colors are (e.g., batch vs. standard).
Whiteness / Yellowness Index (when relevant)
Useful for polymers, papers, coatings, and products sensitive to yellowing.
Spectral reflectance curve (spectrophotometer-based)
Helpful for deeper understanding of pigment behavior and shade shifts.

Why Color Measurement Matters

Color issues can be caused by raw material differences, process drift, contamination, degradation, or environmental exposure. Colorimetry helps you:

control batch consistency and reduce rejects
ensure supplier-to-supplier or lot-to-lot uniformity
confirm color matching to a standard
quantify discoloration after UV, heat, humidity, or chemical exposure
detect early signs of oxidation, aging, or formulation changes
support customer requirements with objective acceptance criteria

Typical Application Scenarios

Quality Control & Batch Release

Verify batch color vs. approved standard
Monitor process stability and detect drift early
Define pass/fail criteria using ΔE limits

Supplier Qualification & Incoming Inspection

Compare incoming raw materials or pigments from different suppliers
Confirm consistency across lots and shipments
Reduce variation in final product appearance

Plastics, Polymers & Masterbatch

Evaluate shade variation and dispersion impact
Measure yellowing after thermal processing or aging
Compare resin grades or additive packages

Coatings, Paints & Inks

Color matching and formulation optimization
Detect discoloration, fading, or whitening
Compare coated parts across production lines

Failure Analysis & Discoloration Investigation

Quantify discoloration on “good vs. bad” parts
Evaluate exposure effects (UV, heat, humidity)
Support root-cause analysis with objective color data

Sample Types

Colorimetry can be performed on many sample forms, including:

molded plastic parts, films, and sheets
coatings on panels or finished products
powders, pellets, and granules (method-dependent)
textiles, paper, packaging materials
consumer product surfaces (case-dependent)

For best reliability, Xinbodi can advise on sample preparation, measurement geometry, and whether multiple measurement locations are needed.

What You Will Receive

Each colorimetry project includes a structured report designed for engineering and QC decisions. A typical deliverable includes:

measurement objective and sample description
instrument and measurement conditions (illumination/observer settings as applicable)
L*a*b* values for each sample and location
ΔE comparison vs. reference/standard (or between samples)
whiteness/yellowness indices when requested
summary tables and clear pass/fail interpretation (if criteria are provided)
recommendations for further testing when color change suggests degradation or contamination
(e.g., compositional analysis, impurity screening, aging tests)

Why Choose Xinbodi for Colorimetry?

Repeatable, standardized measurement methods for reliable QC data
Support for “standard vs. batch” and “good vs. bad” comparisons
Practical interpretation aligned with real production and customer acceptance needs
Ability to connect color change with follow-up analytical workflows
Confidential handling of proprietary products and formulations