Here you can find some references to third pary articles and publications about the usage of DVD+R DL technology in professional (authoring / archiving) applications.

Dual Layer Recordable DVD
Dr. Wlodek S. Mischke
Business Development Manager, DaTARIUS Group

Implementation of the dual layer to DVD+R formats seems to further consolidate the technological advantage of this medium, already evident in the recording speed race. The design of DVD+R DL imitates that of DVD-9. The dual layer discs consist of a substrate with an embossed spiral groove structure, the same type as 'normal' DVD+R. This groove is coated by spinning with the appropriate dye. Restrictions on the dye coating and drying are very much the same as for DVDR media. Then a metal semi-reflective layer must be vacuum coated, or simply sputtered. Crucially, the reflective layer homogeneity over the entire disc's surface should be at least the same, if not more, stringent than for standard DVD-9. Moreover, this reflective film has to fulfil a strict heat conduction condition for good data recording.
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Building and Burning Dual Layer DVD
Stephen F. Nathans
eMedia Live

The availability of DVD+R DL media has the potential to change DVD authoring in two significant ways: First, it will allow pro DVD authors who were already doing DVD-9 titles to check-disc their projects on cheap, disposable recordable media in standard DVD players. With the matrix of players out there now and the widening reliability and compatibility gap between high- and low-end players, this is a huge advantage, and will be realized almost immediately.
The other potential change affects the broader authoring community. As mid-level, prosumer, and consumer authoring tools incorporate dual-layer capability and build in support for dual-layer drives and media, more and more authors can start thinking in terms of project sizes beyond 4.7GB, encoding large video filesets at higher bit-rates, and knowing that they can publish their dual-layer titles on the modest scale available via duplicators and duplication services.
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