Purpose of Test
The colorfastness to crocking test method measures color transfer of a colored textile to other surfaces by rubbing.
This test method is used for textiles made from various fibers and with various coloring types:
- Other Fabrics
- Other Coloring Techniques
Colorfastness – Colorfastness is a fabric’s ability to retain its color in various conditions.
Crocking – Crocking refers to the rubbing off of color from fabric when subjected to abrasion.
Chromatic Transference Scale – The Chromatic Transference Scale is used to visually measure color transfer or staining during the test. The scale has multiple hues that allow a tester to match a hue from a color transfer test to a numerical score.
Gray Scale for Staining – The Gray Scale for Staining is used in colorfastness tests to evaluate staining on undyed textiles. The scale has shades of gray correlated with numbers that allow a tester to match shades with a numerical rating.
Instrumental Assessment of Degree of Staining — An alternative to the visual method of evaluating staining.
Materials Used for Test
- White crock test cloth squares
- Colored test specimen
- Gray Scale for Staining
- Chromatic Transference Scale
Timing of Test – The colorfastness to crocking test may be performed before or after any of the following:
- Any other relevant cleaning or finishing treatments
Test Procedure (Summary)
Part 1: Rub Test – The textile being tested is mounted on the Crockmeter and rubbed with a white crock test cloth under controlled conditions.
Part 2: Assessment & Grading – The color transfer to the white test cloth is assessed by comparing it with one of the following options:
- The Gray Scale for Staining,
- The Chromatic Transference Scale, or
- The Instrumental Assessment of Degree of Staining
A rating is assigned and evaluated against an acceptable quality limit.