You see things because they scatter light towards your eyes. Very small particles called nanoparticles are added to plastics to change their properties. Nanoparticles strongly scatter light! The photograph shows our attempts to reduce light scattering in plastics containing nanoparticles. Two plastic samples were placed side by side. As the laser beam penetrates the disk from the left side, you can see an intense red beam crossing the disk because light is being strongly scattered towards your eyes by the nanoparticles. However, the beam goes through the right disk almost unnoticed thanks to specially engineered nanoparticles that reduce light scattering.