Interaction between vector solitons and solitonic gluons. 
We describe a physical mechanism for creating multisoliton bound states by which optical solitons are glued together by attraction between the nonsoliton beams that they guide, solitonic gluons.  We verify the concept of the solitonic gluons experimentally, observing a suppression of the repulsion between dark solitons owing to an attractive force acting between out-of-phase bright guided beams.