One significant difference between Blu-ray and other current optical disc formats is its requirement to have the recording layer very near the surface, which is protected by just a 100 micron thick solvent-casted polycarbonate film.  While having the recording layer near the surface makes it more vulnerable to scratches, this actually gives Blu-ray an advantage of being able to use any material within the disc, including opaque and coloured materials.

As a result, Sabic Innovative Plastics is now testing its Noryl compound as a potential replacement for polycarbonate, the main material currently used in pretty much all optical discs.  Unlike polycarbonate, Noryl does not absorb moisture, features a superior dimensional stability and requires a less complicated moulding process.  This will also lead to cheaper and quicker Blu-ray disc replication, as the costly moisture-barrier layer and lacquer coating are not required for Noryl material, thus also reducing the number of steps required to produce each disc.

Further details can be read in this Design News article.