nontranslucent

Nontranslucent is an adjective used to describe a material or object that does not allow light to pass through it, or only allows it to pass through in a very limited and diffused manner. This is in contrast to transparent materials, which allow light to pass through clearly, and translucent materials, which allow light to pass through but scatter it, making objects on the other side indistinct.

A nontranslucent object blocks light entirely. If you were to place a light source behind a nontranslucent object, no light would be visible on the other side. Common examples of nontranslucent materials include wood, metal, stone, and most plastics. These materials are often used in applications where opacity is desired for privacy, structural integrity, or aesthetic purposes. The degree to which a material is nontranslucent is often referred to as its opacity. A perfectly opaque material is completely nontranslucent. Conversely, a material that is slightly nontranslucent, meaning a very small amount of light can penetrate it, might be described as having low translucency rather than being fully nontranslucent. The term nontranslucent is a straightforward descriptor for the absence of transparency and significant translucency.