Why is there a verification fabric for AATCC wet and dry rubbing, but dry rubbing only for ISO 105-X12?

AATCC 8 states that both wet and dry rubbing should be carried out to verify the apparatus and the method. The verification fabric (stock code 702-433) is compliant and can be used.

The water uptake for the wet rubbing part of this method is 65 ± 5%.

ISO 105-X12 states that only dry rubbing needs to be carried out to verify the apparatus and the method. The same verification fabric (stock code 702-433) is compliant, but for dry rubbing only. The water uptake for the wet rubbing part of this method is 95 to 100%.

As there are differential water uptake amounts between these standards, the ISO results would not be comparable with the AATCC specification.

This does not indicate a fault with the verification fabric.