The general governing equations for radiating spines are solved to determine the general relationships for spine dimensions, the heat transfer characteristics under the optimum condition, and a least material profile among radiating spines. Similar to convecting spines, the optimum shapes of the radiating spines become wider at the base and longer in height. The optimum heat transfer rate is found to be proportional to the three-fifths power of the spine volume, and the spine profile with the larger value of n is shown to be always superior in terms of heat dissipation per unit volume or mass. From the optimum temperature distribution of radiating spine profiles of least material, the slope of the temperature curve at the spine tip is shown to approach infinity, though the heat flux is equal to zero at the spine tip.