where I λ λ s u n is the emission spectrum of the sun, and ε ε λ λ E b λ λ ( λ λ , T ) is the emission spectrum of the paint. Although, by Kirchhoff's law, ε ε λ λ = α α λ λ in the above equations, the above averages α α s u n and ε ε p a i n t are not generally equal to each other. The white paint will serve as a very good insulator against solar radiation, because it is very reflective of the solar radiation, and although it therefore emits poorly in the solar band, its temperature will be around room temperature, and it will emit whatever radiation it has absorbed in the infrared, where its emission coefficient is high.