This is a great method. However I experienced difficulty sourcing a metal or plastic rod of appropriate diameter. I had the idea of using a wooden rod so after a little searching around I found a suitable diameter of cane (which has a smooth surface) from the greenhouse and I cut the cane down to a suitable length. This works very well with the advantage that the inner sticky tape (with its smooth side in) can be secured with a pin so that its tendency to slip along the rod can be overcome when winding the tape down the rod.