This study is in agreement with the findings of Lord (1961) that micronaire is not equivalent to fineness and highlighted the need for using fineness when estimating FD for use as a selection criterion. FDfin gave a more accurate estimation by eliminating the effect of maturity ratio, preventing false values that FDmic can provide. In situations where breeding programmes have limited resources, FDmic could be used for larger early breeding generations and FDfin in more advanced generations when sample sizes are reduced. This is only advised when the breeder is fully aware of the effect of fibre maturity and under environmental conditions that result in stable fibre maturity ratio. A dedicated effort towards recognising fineness as an important fibre property, as distinct from micronaire, as well as measuring FD would require an additional instrument such as AFIS or Cottonscope to be purchased or available. In the long term, that such investment is worthwhile in a cotton breeding programme for genuine improvement in fibre fineness.