Abstract: A marbleized thermplastic-resin strand is made from a matrix resin and an inlay resin in an apparatus having a die forming a passage extending along an axis and havng an upstream inlet end and a downstream outlet end and an extruder for injecting the matrix resin in hot liquefied condition into the passage at the upstream end thereof such that the resin emerges from the downstrea end. An inlay nozzle opens into the passage between its ends and extends through the die along a nozzle axis not parallel to the passage axis. The inlay resin is fed in hot liquefied condition through the nozzle into the passage such that the inlay resin mixes with the matrix resin. The inlay nozzle is rotated substantially continuously about its nozzle axis so long as the extruder is operating. Thus the patterning of the inlay resin in the matrix resin is a function of the rotation speed of the inlay nozzle.