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The “new paint” in the 2020 coverage is an experimental Purdue formulation, not a general name for white or heat-reflective paint. It combines calcium-carbonate particles in acrylic paint to reflect sunlight and release heat as infrared radiation that can escape through a part of the atmosphere called the sky window.
What is the “new paint”?
It is a radiative-cooling paint formulation described in a 2020 Purdue University study and reported by the BBC. Its particles are calcium carbonate, dispersed in an acrylic paint. It is distinct from ordinary white paint and from later Purdue formulations using different materials. Purdue’s study summary and the BBC report describe the experimental version.
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How does it cool a surface?
The paint works passively through two effects: it reflects much of the incoming sunlight, limiting the energy the surface absorbs, and emits thermal radiation in an infrared range that can pass through the atmosphere toward space. The Purdue study calls this range the “sky window.” The paint does not make cold or use an active cooling system; it changes how energy moves between the surface, sunlight and the sky.
1. It reflects sunlight
White appearance alone does not show how much sunlight a paint reflects. The calcium-carbonate particles in this formulation were made in varied sizes. Different sizes scatter different wavelengths effectively, so a mix of sizes scatters a broader range of sunlight. As Purdue professor and study author Xiulin Ruan put it in the BBC report: “Sunlight is a broad spectrum of wavelengths.” He also explained: “We know that each particle size can only scatter one wavelength effectively so we decided to use different particle sizes to scatter all the wavelengths.”
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- COOL-CORE TECHNOLOGY: This heat reflective paint features "cool-core" technology – specialized pigments that repel heat gain to keep interiors cooler and help save on cooling costs.
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2. It emits heat through the sky window
A surface can also lose heat by emitting infrared radiation. The atmosphere blocks some infrared wavelengths but allows others to pass through. By emitting strongly in this atmospheric “window,” the paint can send thermal energy away from the coated surface and toward space. Combined with low solar absorption, this can allow a surface to become cooler than the surrounding air under suitable conditions.
What did the 2020 study measure?
The figures below are results reported for the Purdue study’s experimental formulation, not guaranteed performance for a product or a roof in every climate. The study reports:
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- 84% initial reflectivity
- 74% Weathered reflectivity
- Rain resistant in 6 hours
- 95.5% solar reflectance—the share of incoming sunlight reflected in the study’s measurements.
- 0.94 normal emissivity in the sky window—a measure of how effectively the surface emitted thermal radiation in that range under the study’s measurement conditions.
- More than 37 W/m² of cooling power in the study’s field tests.
- A tested surface temperature more than 1.7°C below ambient at noon during field testing.
The BBC separately reported a field observation of 1.7°C below ambient in direct sunlight and up to 10°C below ambient at night. Those are reported observations, not a specification that every application should expect. Surface results depend on test conditions and installation; the cited sources do not establish a universal result for buildings.
Is it the same as white roof paint?
No. A conventional white or cool-roof coating may reflect sunlight and reduce heat gain, but that does not establish that it uses the Purdue formulation, emits as effectively through the sky window, or can cool below ambient. The cited sources do not provide a head-to-head test against a named retail coating, so they do not support declaring one type a universal winner. Useful comparison measures include solar reflectance, thermal emittance, measured surface temperature relative to ambient, and evidence of outdoor durability.
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- ROOF COATING - This fortified acrylic roof coating is designed to cool roofs and provide energy cost savings. With a 10-year protection you won’t have to worry about reapplying every year. Dries white.
- VARIETY OF SURFACES - Roof coating can be applied to a many surfaces including EDPM rubber roofs, polyurethane foam, modified bitumen, asphalt, mobile homes and RV’s, concrete, wood and more. Not for gravel, dead level (flat), or shingled roof surfaces.
- COVERAGE - Just one gallon of this roof coating will cover approximately 50-70 square feet per coat. We recommend two coats for best coverage.
- TEMPERATURE - When applying this elastomeric roof coating the temperature must be a minimum of 60°F and rising. Note: Do not apply when temperature is expected to drop below 60°F within a 24 hour period.
- DRYING TIME - This reflective roof coating dries to the touch within 2-3 hours. Please wait 6-8 hours before applying the second coat.
Can you buy the exact paint?
The sources establish research and continuing commercialization interest, not current retail availability of the exact 2020 calcium-carbonate formula. In October 2020, the BBC reported that long-term reliability and efficiency still needed testing before commercial availability. Purdue’s lab news page later noted that a commercialization-focused postdoctoral fellow would begin work on white radiative-cooling technology in January 2025. A 2025 U.S. Department of Energy laboratory report discusses applying radiative-cooling paints to warehouses. These developments show work toward practical use, but do not verify that the original formulation is for sale.
Purdue also studied a later barium-sulfate formulation; it is a different paint, not a renamed version of the calcium-carbonate acrylic formula covered in the 2020 report. The formulations and their reported performance should not be conflated.
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Quick Recap
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- Ames Maximum-Stretch is a white, elastomeric, acrylic, rubberized roof coating & sealant with 650% elongation to resist cracking & peeling. With 88% light reflectivity, the bright white finish reduces surface temperatures resulting in lowered cooling costs.
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- 650% elongation - does not flake, chip or peel - elastomeric and rubberized coating and sealant. Rubber roofing material is 88% light reflective resulting in lowered cooling costs. Brush, roll or spray on!
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- 10 Year Warranty
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- Cool Roof Technology with 80% reflectivity provides excellent energy cost savings
- Resists cracking in temperatures as low as -10 degrees Fahrenheit
- Ideal for metal roofs, concrete, modified bitumen, built-up, and weathered single-ply roofing systems
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
