100% Pima cotton. Single strand. One ply is equivalent to size #8 pearl cotton. 36 yards per skein. These fibers are hand-painted and permanent. They are dyed in small amounts so each batch will vary in distribution of color and in intensity. While this adds character to the fiber, it is advisable to purchase enough thread for a large project at one time. Caution: pre-rinse reds before stitching. The image shows overdyed thread colors, but colors may vary depending on dye lots or your computer or monitor settings.