Question

There are standard tests to determine the colour fastness of dyed materials. A crockmeter is a device to measure:

• A. \( \text{light fastness} \)
• B. \( \text{rub fastness} \)
• C. \( \text{perspiration fastness} \)
• D. \( \text{wash fastness} \)

Hint:

Ever had a pair of dark jeans turn your white sneakers blue? That is an example of poor "rub fastness" (crocking).

Answer 1

The Correct Option is B

Concept: Color fastness testing simulates the conditions a fabric will face during its lifetime to see if it will lose or transfer color.

Step 1: Identify the function of a crockmeter.
A Crockmeter is a standard laboratory instrument used to determine the rub fastness (also called "crocking") of a dyed textile. It rubs a standard white "crock square" (cloth) against the test fabric for a specific number of cycles under a controlled weight.

Step 2: Understand the results.
If color transfers onto the white cloth, the fabric has "poor crocking" or rub fastness. This is tested in both dry and wet conditions.