reflectance; reflectivity
Technical term used in physics, optics, and engineering to describe the fraction of incident light or radiation reflected by a surface.
This paint has high reflectance, so it can reduce summer heat.
The reflectance of a mirror is close to nearly 100 percent.
background reflectance
Compound of 反射 (reflection) + 率 (rate, ratio). A straightforward technical term formed from standard Sino-Japanese elements.