The degree of UV protection afforded by nano-ZnO in a polyurethane/acrylic clear topcoat was investigated. The influence of nano-ZnO concentration and dry film thickness on the optical properties (e.g., UV permeability and visible transmittance) of the coating was probed using a library of 28 samples that were prepared by high throughput techniques. A model for predicting the UV permeability of nano-ZnO filled coatings was developed and the nano-ZnO loading condition required to block >99% UV radiation was determined to be 2.0 g/m2. This model can be used to assist in the development of coatings and other polymeric systems embedded with nano-ZnO to protect the coating and underlying materials (i.e., substrate) from UV degradation.