In a plastic tube for yarn bobbins having a substantially cylindrical body one end is broader than the other so that two tubes can be axially inserted into each other. The broad end is provided with perforations for through flow of dye liquid whereas the narrow end is without perforations. The tube is provided with longitudinal ribs to carry the yarn. These ribs connect the two ends of the tube. Thereby an annular opening is established which is bridged only by the ribs. Dye liquid can from this opening enter the passages on the narrow end bounded by the ribs and the yarn.
