is first wound onto the marking roller 12 a disperse dye is vaporized and supplied to the interior of the marking roller 12 the heated and vaporized dye passes through one or more openings in the marking roller 12 and impregnates the line the location of the openings and the circumference of the roller 12 determine the increments between the marks referring now to fig2 the marking roller 12 is shown in more detail the marking roller 12 comprises a generally cylindrical roller tube 22 made from thin walled metal tubing the interior of the roller 12 defines a dye chamber 24 which contains the vaporized disperse dye a slot 26 is formed in the wall of the roller tube 22 which communicates with the dye chamber 24 in the roller tube 12 the slot 26 extends parallel to the axis of the roller tube and terminates short of the ends of the roller tube 22 the disclosed embodiment shows a single slot 26 however it should be understood that any number of slots 26 can be used limited only by the size of the tube the roller tube 22 is rotatably mounted on sealed bearings 28 which are journalled around a pipe fitting 30 the outer surface of the roller tube 22 may include a continuous helical groove 32 to assure proper tracking of the line as it moves across the roller tube 22 the drive means 18 is provided for rotating the marking roller 12 in the embodiment shown the drive means 18 comprises a kiss roller 34 which contacts the line wound on the marking roller 12 the kiss roller 34 is mounted on a roller shaft 36 which is driven by a motor not shown the surface.