A bullseye lantern (frame) frame is used to make bullseye lanterns, which are used as a light source to illuminate darkened areas. To make the steel frames Smithing of level 49 and a steel bar are required. Glass lenses for the frames can be made with level 49 Crafting by blowing glass; however, a cut sapphire can be used in place of the lens. Lamp oil, obtained by distilling swamp tar at the chemist's in Rimmington, is used to fuel bullseye lanterns. You will need 1 swamp tar to make the oil. Bullseye lanterns can be lit using a tinderbox at level 49 Firemaking.
This item is listed in the Quick Chat system. Because of the different metals also listed, however, it is possible to say nonsense things like "I am smithing: Gold Bullseye lantern frames."