Cooling can be achieved by active cooling or passive cooling. Active cooling involves the consumption of energy to cool an object (e.g., paying for external energy), whereas passive cooling requires no energy from an external source to cool an object (e.g., natural, no-cost energy transfer). Radiative cooling is the process by which an object loses heat by thermal radiation (e.g., electromagnetic radiation generated by thermal motion of charged particles in matter). Passive radiative cooling refers to losing heat by thermal radiation to an external thermal sink, without the consumption of energy. A subset of passive cooling systems operate even when the objects to be cooled are exposed to sunlight. Such daylight passive radiative cooling materials include for example multilayer inorganic films, coating formulations including glass microspheres, and multilayer polymer films with a silver reflector.