Highly stable films containing semiconductor nanoparticles (“quantum dots”) are prepared from resins containing a fast-curing inner phase having a high glass transition temperature (Tg) and certain inner phase/outer phase combinations. The resins may comprise an inner phase and outer phase (but may appear to be a single phase due to their homogeneous appearance when viewed using an optical microscope). The method provides a highly scalable and cost-effective procedure for preparing films that are resistant to light, elevated temperatures, moisture, and oxygen.