Abstract: Process for dyeing substantially undrawn dry-spun filaments of acrylonitrile polymer which comprises extracting spinning solvent from moistened dry-spun filaments of acrylonitrile polymer to below 10% by weight of the filaments and at below 80.degree.C., dyeing the extracted filaments in a dye bath at below 80.degree.C. by initially contacting the filaments with the dye at nearly zero stretch, followed by stretching the filaments from 1.5.times. to 4.5.times. at between 60.degree. - 80.degree.C. while still contacting the dye solution.

Abstract: synthetic organic fibers are dyed to a dark brown to black shade with a mixture of dyes, one of the dyes in the mixture being a green to blue dye having an absorption spectrum in which the peak value of absorbance is between 600 and 700 nanometers, said green to blue dye being further characterized in that the ratio of absorbance at 700 nanometers to the absorbance at the peak value between 600 and 700 nanometers is at least 0.05. The presence of this green to blue dye reduces or eliminates transmittance of red light along the fiber axis, so that no reddish glow is seen when the ends of the fibers are observed. The dark brown to black fibers are thus well suited for use in artificial furs.