Although disc-based storage is not as widely used as it once was for digital evidence archiving, it remains a viable solution when properly implemented and managed. In fact, many of the world’s largest technology companies are using and/or exploring disc-based storage systems for long-term offline storage of petabytes of customer data (e.g. Facebook uses 10,000 Blu-ray discs to store 'cold' data). They do so, however, in a managed environment with a thorough understanding of the medium’s strengths and limitations.
Many in law enforcement use write-once disc-based media for MASTER evidence storage, as it continues to be recommended via various industry best practice documents. Unfortunately, not everyone involved in the evidence chain understands the limitations and best practices as they relate to the care and handling of disc-based media. Adhesive labels, permanent markers, and ballpoint pens have destroyed more evidence than I care to even think about.
There are a number of great resources out there relating to the proper care and handling of disc-based media, as well as resources and guides regarding the various grades and sources of disc-based media. Below are few related links you may find helpful:
Care and Handling of CDs and DVDs: A Guide for Librarians and Archivists (NIST/CLIR, 2003 – PDF)
Care and Handling of CDs and DVDs: A Guide for Librarians and Archivists (NIST/CLIR, 2003 – HTML)
Blank DVD Media Quality Review (DigitalFAQ.com)
If you're already familiar with these and/or other similar resources, consider taking a moment to share them with your peers and colleagues. If they're already familiar with them, feel free to blame me for the redundancy. I'd much rather deal with that than having to tell a prosecutor or investigator that they destoryed their own MASTER evidence.