Multilayer optical film

Thermoplastic birefringent multilayer optical film are disclosed. More specifically, have a linear layer properties, a thermoplastic multilayer film comprising a first layer and a second layer overlapping alternately, both outer layers of the thermoplastic birefringent multilayer optical films is less than 350 nm, thicker than 150 nm, the thermoplastic multi-layer film is disclosed. Thermoplastic birefringent multilayer optical film having a thinner outer protective boundary layer is disclosed.