The results obtained in the optimization of NbTi superconductors are set forth. The intermediate annealing temperature is discussed and the influence of final forming on the critical current density and the reduced pinning force is studied. For the types of conductors investigated (1, 19, 55-core conductors), thejcmaximum occurs at different degrees of final forming; it drops as the filament diameter decreases. As to the reduced pinning force, an increase in the number of cores ora reduction of the filament diameters results in a displacement of the maximum and, for optimized conductors, an extension of the maximum towaras higher fields is obtained. A final heat treatment makes thej~-values drop.