An optical stack includes a first liquid crystal layer and a j-retarder
disposed on the liquid crystal layer. The j-retarder includes a
simultaneous biaxally stretched polymeric film being substantially
non-absorbing and non-scattering for at least one polarization state of
visible light. The j-retarder has x, y, and z orthogonal indices of
refraction where at least two of the orthogonal indices of refraction are
not equal, an in-plane retardance being 100 nm or less and an
out-of-plane retardance being 50 nm or greater.