What makes white, white?
It sounds like a simple question, but when we talk about “white” in the textile world, there are a few specialized concepts that need to be understood. Here's a breakdown of what you need to know if you’re going to be measuring or assessing white fabrics.
Brightening Agents (OBA/FWA): Many bright white fabrics contain additives called Optical Brightening Agents (OBAs) or Fluorescent Whitening Agents (FWAs). These two terms are interchangeable. Their job is to make whites appear brighter and more vivid.
The Side Effect - Intrinsic Shade: Adding brightening agents also comes with the introduction of a subtle color or tint to the white, often blue, violet, or red, for example. This is called the intrinsic shade, and it needs to be determined during assessment.
Measuring It Correctly: Due to the added brightening agents, you need to make sure you have calibrated your spectrophotometer using a UV Calibration tile. Your measurements will be off if you skip this step!
Did you know you can purchase a UV calibration tile from natific? You can find it on the natific portal, or contact us to learn more.
Whiteness Indices: How White Gets Evaluated
Colors and optically brightened whites are assessed using different indices. For white shades, the traditionally used indices are CIE Whiteness and Tint. The issue with these traditional metrics was that a shade could pass the tolerances using these metrics, but the visual match might be far off the standard.
To address this industry challenge, natific developed additional indices that account for fluorescence, bluing, shading, and intrinsic shade. All these indices are combined into the singular natific Whiteness Delta E (nWDE) and are built into natific software. By following the intelligence and auto correction instructions built into the software you will achieve a better digital and visual match to the standard.
What if there is no brightening agent? If a very light shade is not optically brightened, it should be measured as any other color. These are shades like light cream, or other pastels.
Let's Recap:
When a brightening agent is used, the added fluorescence and intrinsic shade must be taken into account.
Make sure your spectrophotometer is properly calibrated with a UV tile when measuring an optically brightened white.
Use all whiteness‑related indices for the most accurate results.
If no brightening agent is present, treat the shade like any other color during measurement.