The fluid absorption rate and retention rate of a sponge are directly related to its basis weight – a measure of the thickness of the material used in its manufacture. For example, Crosstex non-woven sponges come in basis weights of 30, 40 and 50 grams (weight per square meter of fabric). 30 gram material is considered a light absorption material suitable for general purposes, while 50 gram is a heavy-duty material offering maximum absorbency.