Able to withstand temperatures of up to 2000° F, these coatings absorb heat and release it later. Use them to improve the thermal efficiency of heaters, furnaces, and ovens to reduce energy costs. Also known as high-emissivity coatings, they have an emissivity rating of 0.9—the closer a material’s rating is to 1.0, the more heat it will absorb and later radiate. Apply with a brush or sprayer.