In order to evaluate dye resistant nep test methods and establish their potential as reference methods, a recent study was conducted on a series of 113 cotton samples of widely varying cotton characteristics. The samples were characterized for dye resistant neps using three test methods. The fiber samples were spun into yarn and knit into sample fabrics which were then dyed and evaluated for dye resistant nep content at five laboratories. The work showed that the various laboratories could not agree on the dye resistant nep content of the fabrics. There was good agreement between an experimental instrument detection technique and eye evaluation of individual fiber neps.