Despite of a severe selection of polymers and additives and of a careful processing, compounds of plastics or rubbers, can be not enough white.(To know the basics, see the first part: Appealing Plastics and Rubbers: White is Beautiful Part I - Overview, Polymer and Processing Effects) To improve their whiteness and appealing white and opacifying fillers can be used, the most used being titanium dioxide, brighteners that absorb UV and reflect them in visible light making the compound brighter with a slightly different shade, often bluish. Moreover the balance gloss/mat can be optimized to enhance the sensorial impact. Of course the obtained nice whiteness must be preserved during all the service life thanks to a suitable protecting system. Outdoor exposure is, perhaps, the most severe ageing factor but heat, neon light, impurities such as transition metals, microbial proliferation and other parameters must be considered.
Carefully selected white mineral fillers can strongly modify the optical behaviour of polymers thanks to their hiding power due to visible light scattering.