Interference light-absorbing coatings are examined using the Salisbury screen structure. Reflection and absorption coefficients both in energy and amplitude form are obtained from the solution of the wave equation. Clear analytical conditions for total absorption at normal wave incidence are derived. A numerical analysis of perfect absorption conditions is performed. Examples of thin-film coating design using the spectral dependences of optical constants of real materials are presented. Cr/ZnSe/Al structure is used to demonstrate achieving perfect absorption using real materials.