River Media DVDR. The professionals best kept secret.

DVD-R is a "write once" technology that can be used in DVD-RW recorders and read by nearly any computer DVD drive or DVD player. DVD-R media uses only cyanine recording dyes which appear violet on the recording side of the disc.

The laser of your DVD-RW drive heats the dye to a temperature of about 200 C, irreversibly melting a pitted pattern into the recording layer. A plastic layer alongside the dye expands into the newly available space creating a pit pattern similar to that of a conventional DVD. Your DVD player reads this highly reflective pattern for playback. Because the plastic layer melts into the dye layer to set the pattern, DVD-R discs cannot be re-recorded.

Unlike a stamped DVD, DVD-Rs are manufactured with a spiral groove (like a phono disc) called the pregroove. It provides a precise track for the writing laser to follow. A DVD player depends on following the recorded track of pits in order to track the spiral path.

A slight wobble in the pregroove in a pre-established pattern generates a frequency used as a carrier signal; the timing information helps regulate servo motors, tracking of the laser assembly, and focus of the beam. Land pre-pits molded into the substrate provide address information and pre-recorded data, used to initiate write operations.

The larger storage capacity of a DVD-R compared to a CD-R is achieved through a smaller pit size and smaller track pitch of the groove spiral which guides the laser beam. Consequently, more pits can be written on the same physical sized disc. In order to write smaller pits onto the recording dye layer a red laser beam with a wavelength of 650 nm (for general use recordable DVD, versus a wavelength of 780 nm for CD-R) is used in conjunction with a higher numerical aperture lens. Because of this shorter wavelength DVD-Rs use different dyes from CD-R to properly absorb this wavelength.

DVD-R discs are composed of two 0.6 mm polycarbonate discs bonded with an adhesive to each other. One contains the laser guiding groove and is coated with the recording dye and a silver alloy or gold reflector. The other layer is an ungrooved "dummy" disc to assure mechanical stability of the sandwich structure and compatibility with the compact disc standard geometry which requires a total disc thickness of about 1.2 mm.

Two methods are typically used to bond the two substrates together:

• Hot-melt method: A thin coat of melted adhesive is spread over each substrate and then the two surfaces are bonded by means of a hydraulic ram.
• UV method: A thin layer of lacquer is distributed over the disc surface to be bonded, either by rotating the disc or through silk screening. Ultraviolet light is then applied to harden the lacquer.

• Extra fast dry inkjet surface - Dry to touch within seconds
• No colour bleeding - Our inkjet formulae utilises special pigment molecules which prevent colour bleeding
• Brilliant White - No off-white or cream finish, when we say white we mean it!
• Thermal Surfaces Optimised for specific printers - River Media offer dedicated discs for both full colour and mono printers








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We're so confident in the quality of our media that should you not be entirely satisfied we'll offer a full refund - no quibble.