opaque

Opacity is a term used to describe the degree of non-transparency of a material. This property often depends on the structure of the material, in particular on differences in the refractive indices within its morphological structure. In the case of unmodified plastics, the haze is influenced by such differences.

Typically, semi-crystalline plastics are opaque, which means that they cannot transmit light completely. One interesting aspect is that opacity tends to increase as the crystallinity of the plastic increases. This means that materials that have a higher order in their structure are more likely to be opaque.