nonreflecting

Her "nonreflecting" paint was overdue for renewal, and K.15 could see her clearly.

It looked like a giant nonreflecting shield of glass, not very thick and amazingly shiny and free of any signs of wear.

A nonreflecting interface separating regions with different refractive indices must be rough, because the laws of reflection and refraction governed by the Fresnel equations for a smooth interface require a reflected ray when the refractive indices of the material and its surroundings differ.