Kriya’s Low Refractive Index (LRI) coating is a solvent based, UV curable coating with a tuneable refractive index (RI) as low as 1.35 for polymeric substrates or optionally available as an inorganic thermal curable coating for glass. It is one of the few PFAS free coatings with this low refractive index available worldwide. It can be used in optical stacks to match the RI requirements in that specific construction. It is frequently used to reduce the reflection of a plastic substrate up to a certain extent, or as part of a waveguide structure to guide light into a specific direction. In combination with a Kriya’s hard coat or Antistatic hard coat as a base layer it is possible to add properties such as additional mechanical and/or antistatic properties. The LRI coating can be applied by standard wet coating techniques such as gravure and slot die, and in combination with the High refractive index layers as offered by Kriya sophisticated anti-reflection coatings can be made.