Fabric surface unevenness and defects are usually created by yarn irregularity and defects in weaving process. These
unevenness and irregularities appear on fabric and affect various fabric properties. In order to investigate weft yarn mass
irregularities on fabric surface unevenness and defects, various plain fabric samples were prepared in which they differ
only in weft yarn mass irregularity. One of the effective factors on fabric surface unevenness is yarn protrusion in fabric
structure. Yarn protrusion in fabric structure is influenced by yarn’s physical and mechanical properties and fabric
structural characteristics. In this work, relationship between mass irregularities of weft yarn and fabric surface
unevenness was investigated using angular power spectrum curve, a measure of yarn protrusion in fabric structures. The
results showed a high significant correlation between these two parameters.