ASTM E313

ASTM E313 is the ASTM standard for calculating yellowness and whiteness indices from instrumentally measured color coordinates. It provides a consistent technical basis for turning measured color data into practical index values that can support product comparison, appearance control, and specification review. For organizations that rely on objective color evaluation, this standard helps reduce ambiguity and improves repeatability across testing and quality workflows.

What is ASTM E313?

ASTM E313, titled Standard Practice for Calculating Yellowness and Whiteness Indices from Instrumentally Measured Color Coordinates, defines a calculation-based approach for deriving whiteness and yellowness values from color measurements. Rather than describing a material property by visual judgment alone, it supports a more objective method using instrumentally measured coordinates. This makes it useful when color appearance must be assessed consistently across batches, suppliers, or test programs. The standard is commonly used as a reference for color index calculations in technical and quality settings.

Where is ASTM E313 used?

ASTM E313 is used wherever whiteness or yellowness needs to be quantified from instrument readings instead of subjective inspection. It is commonly applied in laboratory testing, incoming inspection, product development, and quality control workflows that compare color appearance over time or between samples. Because it focuses on calculated indices, it is especially relevant when evaluating materials or products where slight shifts in color can affect acceptance, consistency, or customer expectations.

Why is ASTM E313 important?

This standard matters because it supports consistent color reporting and helps organizations make clearer decisions based on measured data. ASTM E313 can improve procurement and production comparisons by providing a repeatable way to calculate whiteness and yellowness indices. That consistency may reduce disputes, strengthen specification compliance, and improve traceability in testing records. For businesses managing color-sensitive products, it offers a practical technical basis for evaluating appearance with less reliance on visual interpretation.

• Calculated whiteness and yellowness indices
• Uses instrumentally measured color coordinates
• Supports objective color comparison
• Useful for quality control and testing
• Helps standardize color evaluation reports