Can you provide an example of a leather rubbing color fastness test using one of the standards you mentioned?

let's take the example of the ISO 11640 standard, which is commonly used for testing the color fastness of leather against rubbing. Here is an example of how the test would be conducted:

1. Sample preparation: Cut out a sample of the leather to be tested, and ensure that it is clean and free from any surface contaminants or coatings. The sample should be at least 40 mm x 100 mm in size.

2. Test method: Secure the leather sample onto the testing apparatus, ensuring that it is flat and taut. Set the rubbing head to move back and forth over the sample for a specified number of cycles, which is typically 10 or 20 cycles.

3. Evaluation: After the rubbing test, evaluate the sample for color transfer, appearance change, and color change. The color transfer is evaluated on a scale of 1 to 5, with 1 being no transfer and 5 being severe transfer. The appearance change is evaluated on a scale of 1 to 5, with 1 being no change and 5 being severe damage. The color change is evaluated on a scale of 1 to 5, with 1 being no change and 5 being severe change.

4. Overall rating: Calculate the overall rating for the sample by combining the scores for color transfer, appearance change, and color change. The overall rating is evaluated on a scale of 1 to 5, with 1 being excellent color fastness and 5 being poor color fastness.

5. Compare results: Compare the overall rating for the tested sample with the standard for the intended application of the leather. For example, if the leather is intended for use in a high-wear area such as a shoe or handbag, a higher rating may be required than for a leather product that is less likely to be exposed to rubbing.

It is important to follow the ISO 11640 standard carefully to ensure accurate and consistent results. This standard provides a reliable and widely accepted method for evaluating the color fastness of leather against rubbing, and is used by many industries and regulatory bodies around the world.