Using CD & DVD for Archival
The consensus of opinions from manufacturers and digital preservation specialists, based on accelerated lifetime testing, is that a high quality CD or DVD, if properly handled and stored, should preserve data for at least 75 years. Studies conducted by Toshiba and Sony even suggest a lifetime as long as 200 years before the data becomes unreadable.
We check our Google Analytics back end UI daily, and some of the keywords that have been popping up in terms of search that brings people to www.standardmedia.ca are things like “Using CD & DVD for Archival”, “CD Replication for Archiving”, “DVD Archives”, and “CD and DVD Archive”. We’ve decided to dedicate a post to the ins and outs of what you should know when deciding to transition into a digital archive using CD or DVD products.
1. I’m In Over My Head. I have thousands of documents that I’ve scanned or need scanned. After that, what do I do?
The clients who have physical paper that they either need scanned, or who have invested countless hours scanning need not worry about what to do after. We’ll tell clients who’ve already done the grunt work to simply either load the data onto an internal FTP if they have one or a hard drive. In essence, if they’ve already done that, they’ve archived the material. However, most don’t take into consideration organization and catalogue. It’s simply just a transfer. You can do one of two things here…leave the data as is in whatever form you’ve saved it, or put some thought into organizing it in an efficient and effective way besides folders. For larger organizations, archived data is in abundance. Scanning through valued folders is still a significant investment of time, and in some cases, developers, admin people, or production staff can’t be spending 10 mins trying to find the file or image they’re looking for. We offer a variation of the custom splash page we’ve developed for CD and DVD projects, that can organize that data in a number of ways with a nifty user interface that makes the experience a little more manageable. The easier the access, not to mention ultimately finding what you’re looking for, the less time searching.
2. Why not just store it on a hard drive/database?
Yes. That is what you should do. What we call “hard archival” or the commitment of the data to the CD or DVD format is best when used as a back up to what would be in a computer database somewhere. We have a few ad agency clients who literally have 20 years worth of concepts, mock ups, and designs in a variety of formats (Corel Draw-Paint-InDesign-Photoshop, etc…) who just want to keep the stuff organized and accessible on the fly. Most of it will never be seen again, but they still want to keep it. It’s essentially a chronological snapshot of intellectual property, and best used as a fail safe backup.
- When archiving, discs that have a gold metal reflective layer are recommended.
- For general storage, a temperature between 4°C (39°F) and 20°C (68°F) is recommended with a relative humidity of 20% to 40%
- For long term storage, 18°C and 40% RH are recommended.
- For extended term archival storage even lower temperature and humidity are recommended.