This invention features a hot melt ink composition. A first axially fixed connector is operatively associated with the first end of the rigid tubing and a second axially fixed connector is operatively associated with the second end of the rigid tubing. 1-bicyclo-octene or -octane compound represented by formula:wherein R is selected from the group consisting of hydrogen, acetate, carbonate monomethyl ester, and allyloxy;and wherein the broken line represents a single or double bond.