Barium hexaferrite films having thickness from 3 to 30 μm were deposited onto 0.5 mm Magnesium Oxide (111) substrates, and were examined by vibrating sample magnetometry, torque magnetometry, x-ray diffraction, and scanning electron microscope measurements. Ferrimagnetic resonance measurements were taken with the magnetic field applied perpendicular to the film plane. The FMR linewidth values for as-produced 3 - 30 μm films was 0.45 - 0.70 kOe, and was reduced to 0.06 - 0.45 kOe after annealing at 1000 °C for 2 hours. Further annealing increased the linewidth. The FMR linewidth for the 30 μm thick film was also found to decrease upon mechanically removing 55 ∼ 77 % of the substrate thickness. A 6-fold in-plane anistropy symmetry in the anisotropy energy was observed in torque magnetometry measurements for films thicker than 30 μm. These results can be interpreted as due to film inhomogeneity, stress, and the growth of small regions of non c-axis textured material.