LS-R economically viable. The need for the disc to be meticulously constructed from many layers of different materials, and the need for the drive to be able to electrically address each layer specifically, may make this solution too expensive for commercialization. In the next generation LS-R may compete with other next-generation optical disc format such as the Holographic versatile disc and Protein-coated disc formats. LS-R LS-R, or the Layer-Selection-Type Recordable Optical Disk, is the term coined by Hitachi in 2003 for a next-generation optical disc technology which allows much larger data storage densities than DVD, HD DVD or Blu-ray Disc, by
Optical disc authoring require writing the entire disc at once, but allow writing of different parts at different times. This allows a user to construct a disc incrementally, as it could be on a rewritable medium like a floppy disk or rewritable CD. However, if the disc is non-rewritable, a given bit can be written only once. Due to this limitation, a non-rewritable disc whose burn failed for any reason cannot be repaired. (Such a disc is colloquially termed a "coaster", a reference to a beverage coaster.) There are many optical disc authoring technologies for optimizing the authoring process and preventing errors. Some