Patent ID: 7648768

Claim:
A coating, comprising: a functional coating comprising: a first dielectric layer comprising a first layer having a quarter wave optical thickness in the range of 0.1 to 1, and a second layer having a quarter wave optical thickness in the range of 0.1 to 1; a first infrared reflective metal layer having a quarter wave optical thickness in the range of 0.005 to 0.1; and a second dielectric layer comprising a first layer having a quarter wave optical thickness in the range of 0.05 to 0.5 and a second layer having a quarter wave optical thickness in the range of 0.1 to 1.5; and a topcoat formed over at least a portion of the functional coating, the topcoat comprising: a first topcoat layer comprising silica having a quarter wave optical thickness in the range of 0.5 to 1.5 with respect to a wavelength of 550 nm; and a second topcoat layer comprising zinc stannate having a quarter wave optical thickness in the range of 0.5 to 1.5 with respect to a wavelength of 550nm, and wherein the topcoat is sufficiently thick so as to affect the optical properties of the coating.