Yellowness Index (YI) ASTM E313

Yellowness Index is a number calculated from spectrophotometric data that describes the change in color of a test sample from clear or white to yellow. This test is most commonly used to evaluate color changes in a material caused by real or simulated outdoor exposure.

Test Procedure:
Test sample packaging, handling, and preparation (preferably no cleaning) can affect the test results by modifying the surface of the sample. Since YI testing is often a series of comparative measurements over extended periods of time, these factors should be defined and documented prior to any testing.

The BYK Gardner Spectrophotometer is highly automated. After specifying the illuminant, observer angle, and the reference color, the test sample is inserted into the specimen holder, and the spectrophotometer takes the reading. Multiple samples should be measured and the readings averaged.

Specimen size:
4" (100 mm) disk

Yellowness Index (YI)

Equipment Used:
X-Rite i7 Colorimeter


**Please note that this test description is intentionally generic in nature and aimed at providing a descriptive summary to enhance test understanding. Standards can be obtained from appropriate standard authorities.



Related Links

royal blue and navy blue polymer beads

Polymers News and Events

NEW SERVICE: CircularAssure - Services to help you close the loop in the circular economy for plastics

ARTICLE: Processability and evaluation programmes for recycled plastic materials

ARTICLE:  Adhesives Quality Assurance Testing Programs

ARTICLE:  Enabling Polymer Non-Wovens Development

CASE STUDY: Polymer Surface Contamination Resolution

CASE STUDY: Polymer Failure - Distribution and Dispersion of Fillers


Contact Intertek