AATCC 141-2019: In the dyeing of acrylic fibers with basic dyes, the classic parameter--e.g., the time of the half-dyeing of individual dyes do not give a true indication of their dyeing behavior in admixture with other basic dyes. Since basic dyes show virtually no migration in acrylic fibers under normal dyeing conditions, compatibility is of major importance in selecting dye combinations with optimum level dyeing behavior. AATCC 141-2019 is intended to determine the behavior of a dye in relation to its compatibility when applied to acrylics.