DVD+R (DVD Recordable) is a recordable medium with an organic dye in its recording layer which does not allow data to be rewritten or deleted once it is written on the disc. DVD+RW (DVD Rewritable), on the other hand, is a rewritable medium with a metallic phase transitioning material in the recording layer, allowing data to be deleted and rewritten.
Both types of media are compatible with the DVD geometry and are used widely in applications that do not adapt well to mass production. When used for data exchange on a personal computer, it seems it is easier to ensure compatibility when the data is recorded using the incremental write method rather than the disc-at-once method. The service life of a recording medium is estimated based on the results of accelerated aging tests. Because a rise in temperature and humidity and ultraviolet light are known to reduce the life of the disc significantly, the disc is best stored in a dry, cool and dark location. Due to a higher recording density compared to CDs, DVD+R and DVD+RW are more susceptible to the effects of soiling such as dust, scratches and fingerprints on the disk surface, and must be handled with care and kept clean.
The various standards for DVD+R and DVD+RW are established by the DVD+RW Alliance (a group comprising companies and organizations involved in the R&D and manufacture of DVD products). As DVD+R and DVD+RW appeared later than DVD-R and DVD-RW, the shortcomings of the predecessors have been rectified and the specifications offer improved recording, deleting and editing on home-use DVD and HDD recorders. The display of the DVD+R and DVD+RW logos on the recording media is subject to approval and a framework is in place to ensure that a minimum standard of quality is met. They are different to DVD-R and DVD-RW in this respect. Recordable and rewritable DVDs are given an encryption key called a media key block (MKB) and a unique media ID during their final manufacturing process. Because DVD+R and DVD+RW can be used on devices that can only read standard DVDs too, the user is able to change the book type contained in the media ID. (To actually change the book type, the drive must be equipped with this function. Moreover, with respect to DVD+R, the book type can no longer be changed once the disc has been written.) The label, DVD±R, found on some drives indicates that the drive is able to read both DVD-R and DVD+R, and does not mean that a “±” version of the recording medium exists. The difference between products labeled “for video” and those labeled “for data” is that the former includes extra charges in the price for private recording compensation.
- The structure of a DVD+R (single-sided single-layer)
- The structure of a DVD+RW (single-sided single-layer)
- If you look at the reading surface at different angles, you can see the color differences. The inside is the recorded area, and the outside is the unrecorded area.
- DVD logos and symbols
- DVD drives and DVD media