Purpose and Scope

This test method provides procedures for measuring the whiteness and tint of textiles.

Whiteness as measured by this test method is an indication of how white the textile appears to an average viewer. Tint, if other than zero, is an indication of a reddish or greenish hue having shifted away from a bluish hue with a dominant wavelength of 466 nm. The formulas for calculation of whiteness and tint are those recommended by the CIE (see 11.1).

Because reflectance is affected by the nature of the surface of the textile, comparisons can be made only between samples of the same type of textile.

The application of the formulas is restricted to specimens that are called "white" commercially, that do not differ much in color and fluorescence, and that are measured on the same instrument at nearly the same time. Within these restrictions, the formulas provide relative, but not absolute, evaluations of whiteness that are adequate for commercial use, when employing measuring instruments having suitable modern and commercially available capabilities.