Polymer-small molecule film or coating having reverse or flat dispersion of retardation

A retarder comprising:

• a layer having a thickness of less than 5 micrometers and comprising a mixture comprising birefringent small molecules and birefringent polymers having a weight ratio of birefringent polymer:birefringent small molecule in a range from 70:30 to 90:10, the birefringent polymers having an in-plane slow axis primarily in a first direction and the birefringent small molecules having an in-plane slow axis substantially orthogonal to the first direction;
• wherein:
• the layer exhibits in-plane retardation values that vary by +/−5% or less in the entire wavelength range from 400 to 700 nanometers or the retarder exhibits an in-plane retardation that increases as a function of wavelength in a wavelength range of 400 to 700 nanometers;
• and
• the mixture comprises the following birefringent small molecules of the following formula:
• or salts thereof.