Physical principles governing the response of coatings to solar and infrared radiation are reviewed. It is shown that the reflection of IR radiation by a paint is controlled primarily by the refractive index and particle size of the pigments in the coating. Pigments are evaluated in terms of reflectance, transparence and hiding power in the NIR region, and criteria for pigment selection for various applications are given in terms of their optical properties. Particular attention is given to raw materials selection, manufacture, and evaluation of coatings with respect to tailoring IR reflectance.

Robert F. Brady, Lindsay V. Wake, Principles and formulations for organic coatings with tailored infrared properties, Progress in Organic Coatings, Volume 20, Issue 1, 1992, Pages 1-25, ISSN 0300-9440, https://doi.org/10.1016/0033-0655(92)85001-C.