The present disclosure generally relates to durable solar mirror films, methods of making durable solar mirror films, and constructions including durable solar mirror films. In one embodiment, the present disclosure relates to a solar mirror film comprising: a multilayer optical film layer including having a coefficient of hygroscopic expansion of less than about 30 ppm per percent relative humidity; and a reflective layer having a coefficient of hygroscopic expansion.
GOVERNMENT LICENSE RIGHTS
 The Government of the United States of America has rights in at least some of the inventions described in this Patent Application pursuant to DE-AC36-08G028308 (CRADA No. 08-316) awarded by the U.S. Department of Energy.