Neps cause significant financial losses to the textile industry. This paper defines different types of cotton neps, their sources and measurements, and the current state of knowledge about research on neps. Generally, a nep is defined as an entanglement of fibres, that can be caused by environmental factors during growth, processing or are inherent to particular varieties. Biological neps are caused by trash particles entangled in the cotton and result in small dark specks in the greige fabric, but are generally removed by wet processing. Mechanical neps can be found in ginned lint, card web, yams and cloth and are strongly influenced by mechanical processing. Classicality, neps are measured by counting them in a card web, but now AFISTM can be used for high-speed measurement of neps in fibre samples. The Uster Evenness Tester measures neps in yarns as short thick spots. linage analysis is being used to quantify white speck neps on dyed fabric. White speck neps contain miniature clusters of fibres and are often not visible as defects until dyeing, rendering the fabric unsuitable for commercial use, resulting in large financial losses. It has been estimated that the U. S. textile industry has had financial losses as high as $200 million per year due to white specks. Initial research has shown strong correlation between AFISTM card sliver data and white speck content of fabric. More research is necessary to establish relationships between bale data and the quality of the finished product. Technology to measure more attributes of cotton on a larger scale is becoming available and research is needed to determine the accuracy of this data. The U. S. & Australia will be collaborating in research to: I) gain fundamental knowledge of the nature and behaviour of cotton and neps; 2) gather baseline data on the level and characteristics of neps in Australian cotton; and 3) predict white specks on fabric using high speed fibre data.