Abstract: A powder toner composition includes a particulate synthetic thermoplastic material, refractory metal oxides, and a powder lubricant. The particulate synthetic thermoplastic material is surface coated with a blend of the refractory metal oxides and the powder lubricant. At least one of the refractory metal oxides is surface-treated. The powder compositions exhibit fluid properties when subjected to mechanical agitation or aeration, and settle as compacted solids when agitation/aeration ceases. The compositions exhibit behavior substantially free of slugging, channeling and jetting when aerated.