Abstract: In conventional processes for coating continuous filaments the filament is handled by various mechanical means such as, rollers, pulleys, etc. In the manufacture of, for example, optical fibers, such handling causes unacceptable mechanical damage to the fiber. Mechanical contact of the fiber being manufactured can be avoided by passing the fiber through a capillary wetted with a curable coating liquid. The flow of the coating liquid through the capillary is limited by reducing the pressure of the ambient above the liquid level within the vessel containing the coating liquid.