A system for in-line treatment of at least one thread is provided. The system is configured to be used with a thread consuming device and comprises a treatment unit having a plurality of nozzles arranged at different positions relative the at least one thread, said at least one thread being in motion in use, each nozzle being configured to dispense one or more coating substances onto the at least one thread when activated; and at least one thread engagement device configured to rotate the at least one thread along its longitudinal axis as the at least one thread moves through said treatment unit.