 This study investigates the wicking properties of natural staple yarns made of cotton and wool, finding that fiber packing density, twist level, number of ply, and fiber diameter affect yarn wicking behavior. Wool yarns with coarser fiber diameters showed the best wicking rates. Pre-wash treatment improved yarn wicking by changing fiber surface condition, while plasma treatment was more effective in increasing yarn wicking rate for both filament and staple yarns. This article was authored by Q. Lee, J. J. Wang, and C. J. Hurran.