Reflectance versus Wavelength Performance Test for Hydroponic Films:

ORCA Grow Film® is 94% reflective across the full visible spectrum, averaging 94% reflectivity for all wavelengths that are relevant for plant stimulation.

 The chart below demonstrates the reflectance vs. wavelength performance of several popular brands and materials used in hydroponic grow rooms. Metalized Polyethylene Terephthalate Film was first developed by DuPont in the 1950's; originally branded as Mylar, it is now commonly known as PET film and manufactured all over the world. Many products in the hydroponic industry are associated with false or misleading performance claims, and this is true of reflective films. PET film products are marketed to hydroponic consumers with performance claims as high as 99% reflectivity, despite historically testing in the low to upper 80% reflectance range in the visible spectrum.

 ORCA Grow Film® incorporates the latest reflective technology from the engineered synthetic materials field, similar to those found in solid-state lighting, flat panel TV's and PDA's.

Have you noticed in LED grow lamps, where there is no heat issue/consideration when choosing a reflector, and where every manufacturer is striving for higher performance, the choice is not a Mylar/PET film, but rather a white reflective material?
The above testing was performed by Orb Optronix. Orb's testing lab is NIST traceable and provides measurement to industry standards including IES, CIE, IEC, ANSI, DOE, CALiPER, and Energy Star.