Architectural metal coatings infused with polychromatic pigments create dynamic visual effects, offering shimmering color shifts that range from subtle to dramatic, changing with sunlight and viewing angles.
Formulated with special effect pigments like pearlescent mica and metallic flakes, these durable finishes are increasingly popular not only for striking exterior appeal, but also due to advancements that make these multi-dimensional looks more cost-effective and efficient.
Nearly two decades ago, PPG introduced DURANAR® VARI-Cool® coatings, the first coil coating system to incorporate these versatile polychromatic pigments. Today, these advanced coatings are available in both Duranar coil and extrusion formulations, providing architects and designers with flexible options.
Evolution of Polychromatic Pigment Technology
Initially, polychromatic pigment technology was available as a two-coat system, consisting of a primer layer followed by a topcoat made of 70% polyvinylidene fluoride (PVDF). This combination delivered exceptional durability, weather resistance, chemical protection, color retention and gloss stability, all enhanced by the unique color-shifting effect.
As the popularity of VARI-Cool increased, architects began requesting customized colors for high-profile projects. To meet this demand cost-effectively, PPG developed the three-layer CORAFLON® MXL system. This advanced coating system includes a primer, a PVDF basecoat, and a fluoroethylene vinyl ether (FEVE) clearcoat embedded with special effect pigments adapted from PPG’s leading automotive coatings.
A key advantage of the Coraflon MXL system is its ability to achieve dimensional effects with fewer color-shifting mica particles, especially when contrasting hues are applied in the basecoat and clearcoat layers. This innovative approach enables a wide range of visual effects, from subtle three-dimensional sparkle to bold color transitions throughout the day.
Showcasing Innovation: Dayton Children’s Hospital
PPG’s proprietary polychromatic pigment coatings have been featured on many landmark buildings, including the award-winning Dayton Children’s Hospital in southwestern Ohio.
PPG partnered with 3A Composites USA on the project that began in 2014.
Champlin Architecture incorporated 3A’s ALUCOBOND® PLUS 4mm aluminum composite panels into the exterior design. Favored by architects for their weather resistance, formability, ease of installation and flame-retardant core, ALUCOBOND panels are manufactured at 3A’s plant in Benton, Kentucky, and finished on 3A’s coil coating lines.
As part of Dayton Children’s rebranding efforts, the goal was to create a campus environment that felt more welcoming, vibrant and modern, conveying hope and healing through color. To achieve this, 3A collaborated with David C. Story, color styling manager for PPG’s Industrial Coatings business, to develop a series of custom hues for consideration.
After extensive color analysis and polling, a multi-dimensional blue-green shade was selected and ultimately named Dayton Blue.
The result is stunning with dramatic color transitions across the exterior cladding from the first morning light to sundown, giving the impression that several different hues were incorporated into the design.
In 2024, Metal Construction News honored 3A Composites USA and their Alucobond aluminum composite panels with the MCM award for their work on the Dayton Children’s Hospital Specialty Care Center. The project was recognized for its innovative use of metal in the exterior design, which showcased the dramatic impact of polychromatic pigments.