Haze
Haze is an internal bulk property, but, because of the importance of appearance, it has been considered along with surface properties due to its relation to gloss (see Figure). Crystallinity, optical defects, ‘fish eyes’, phase separation of blends, contaminants, gel particles and dispersion of pigments (carbon black) are structures that increase haze. Haze is the internal scattering of light. Haze makes it difficult to clearly see all object through a film as a result of the interference from randomly scattered light reaching the viewer in addition to light coming straight from the object. Smaller crystals provided by a nucleating agent will decrease haze. The other phenomena described above can also be reduced by nucleating agents, better formulation and processing.