archival cd-r - really true?

On recordable CDs, the data is on the label side and scratches can remove the data. On DVDs, the data is inside the media, between two layers of plastic. Scratches cannot permanently destroy the data proper as they can with CDs. The risk is that DVDs can delaminate, which will destroy them. Also, air getting in between the two plastic layers laminated together (with the data between them) can destroy the data by oxidizing the dye layer. This form of failure occurs from the outside in. A logical suggestion that is often made is to not use the last 10% to 20% of the media to increase it's resistance to this form of deterioration. Also, it is critical to avoid any storage or handling that flexes the media even slightly. I don't buy the "spiral track" argument that was made against optical media. These are "random access" media, not sequential access. If you don't believe it, put a full data CD or DVD into your drive and read any file from the CD. You can hear the "seeking", and the time required to get to a file is clearly nothing like the time that would be required to read from the start of the disc to the selected file. The condition of the middle of the disc has no bearing on the readability of data at the end of the disc unless, on a particular disc, a directory or some other critical data structure just happens to fall in a defective area. I think that most of the problems that we see are really with bad burners, and this can mean marginally bad burners (no indication of a problem, but the laser is weak and the media is not heated to the proper temperature, and may subsequently "fade" as a consequence). My own experience (I repair computers and see more drives than most people) have convinced me to stay with Samsung for CDs and Pioneer for DVDs (although Pioneer had one bad model, the "09's"). Other than that, I'm convinced that well burned optical media is the best storage media we have ever had, but I think that the media is the very least of the issues. Burning, storage and handling, I think, are every bit as important as the media itself. Two very important rules: NEVER use "RW" media of any kind, and never use "packet writing" to burn your media (e.g. stick with ISO-compatible formats).