This investigation was carried out at Al-Amria Spinning and Weaving Company to study the impact of Micronaire reading on neps formation during cotton yarn processing. Four micronaire readings i.e., (4.49 for Giza 86, 4.27 for Greece upland cotton, 4.23 for Giza 80 and 4.08 Giza 88) and four yarn counts i.e., (50, 80 Ne for combed yarns and 24, 30 for carded yarn). The obtained results could be summarized as follow:

The highest fiber length (UHML), uniformity index and fiber elongation were recorded for Giza 88 was the lowest micronaire reading (4.08).
The lowest number of neps was associated with the intermediate micronaire value 4.23 and card sliver stages. While, the lowest micronaire reading 4.08 of Giza 88 recorded the lowest number of neps at yarn stage.
The increase in yarn strength, yarn evenness CV%, thin, thick and number of neps  were a compared with the  micronaire reading increase for Giza 86 and Giza 88.
The highest yarn strength with the lowest evenness CV% and imperfections i.e., thin, thick places and number of neps were attained using the lowest yarn count.
Most fiber and yarn properties of the studied four cotton varieties were negatively correlated.