The invention relates to a continuous dry spinning process for preparing a fiber from a polymer solution having concentrations of polymer, salt, solvent and water. After the fiber is extruded and quenched, the fiber is placed in contact with a conditioning solution comprising concentrations of solvent, salt, and water. The conditioning solution acts upon the fiber to plasticize the fiber prior to being drawn. The conditioning solution has concentrations of solvent, salt, and water so that the fiber is plasticized to the extent necessary for drawing but does not plasticize the fiber to such an extent as to re-dissolve the fiber into a polymeric solution. A heat-treated fiber manufactured from this process has improved shrinkage and can be colored to darker shades.