CD longevity tips
MERRICK
In the studio or on a stage
I thought I'd share tips I've collected that pertain to preserving CD media. I presume these tips also apply to DVD media as well:)
First an article about the bad news:
http://www.cdfreaks.com/news/7751
"The tests showed that a number of CD-Rs had become completely unreadable while others could only be read back partially. Data that was recorded 20 months ago had become unreadable. These included discs of well known and lesser known manufacturers..."
Some tips I've gathered through the cough...cough ages:
1) Don't use an alcohol based pen like Sharpie. These pens eat into the CD plastic and will corrupt data. Use a pen specially formulated for CD writing I believe Maxell makes one and TEAC makes one. They are under $3. Hard to find in office supply stores but a good music instrument store (got mine at Sam Ash) should have them.
If you have no choice but to use a traditional marker, write only on the clear plastic inner ring.
2) Keep your CD out of direct light even room incandecent light. Light bleaches the dye. I keep my blanks in a dark closet (with my other secrets) and I keep my burned CDs in a dedicated CD file box.
3) Store your CDs flat! The dye is technically a liquid and will follow gravity over time thus corrupting data if it is stood on end.
4) Important data? Making secondary and even ternary backups? use different brands of CD. This gives you a better chance of long term survival in the event that one brand is inherently of poor quality.
5) From:
http://www.cybertechhelp.com/forums/showthread.php?p=133723#post133723
"I cannot remember where I read the full article, slashdot maybe, where they stated that disks burned at lower speeds lasted longer due to the amount of burn into the disc. Faster speeds mean that the laser is not concentrated on the same spot as long as at slower speeds so I would assume that has an effect on the depth of the pattern burned and over time shallow impressions would wear away.
It sounds pretty plausible to me."
I have not tried this one (#5) yet but I think I will.
One other thing, Read this guide on updating/installing ASPI layers. This is a must have article (2 pages). Most impressive:
http://aspi.radified.com/
First an article about the bad news:
http://www.cdfreaks.com/news/7751
"The tests showed that a number of CD-Rs had become completely unreadable while others could only be read back partially. Data that was recorded 20 months ago had become unreadable. These included discs of well known and lesser known manufacturers..."
Some tips I've gathered through the cough...cough ages:
1) Don't use an alcohol based pen like Sharpie. These pens eat into the CD plastic and will corrupt data. Use a pen specially formulated for CD writing I believe Maxell makes one and TEAC makes one. They are under $3. Hard to find in office supply stores but a good music instrument store (got mine at Sam Ash) should have them.
If you have no choice but to use a traditional marker, write only on the clear plastic inner ring.
2) Keep your CD out of direct light even room incandecent light. Light bleaches the dye. I keep my blanks in a dark closet (with my other secrets) and I keep my burned CDs in a dedicated CD file box.
3) Store your CDs flat! The dye is technically a liquid and will follow gravity over time thus corrupting data if it is stood on end.
4) Important data? Making secondary and even ternary backups? use different brands of CD. This gives you a better chance of long term survival in the event that one brand is inherently of poor quality.
5) From:
http://www.cybertechhelp.com/forums/showthread.php?p=133723#post133723
"I cannot remember where I read the full article, slashdot maybe, where they stated that disks burned at lower speeds lasted longer due to the amount of burn into the disc. Faster speeds mean that the laser is not concentrated on the same spot as long as at slower speeds so I would assume that has an effect on the depth of the pattern burned and over time shallow impressions would wear away.
It sounds pretty plausible to me."
I have not tried this one (#5) yet but I think I will.
One other thing, Read this guide on updating/installing ASPI layers. This is a must have article (2 pages). Most impressive:
http://aspi.radified.com/
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Comments
I forgot the first commandment! Keep the media away from extreme temperatures and humidity levels.
Great link here (thanks to psychocandy from cybertechhelp.com)
http://www.osta.org/technology/cdqa13.htm
"How long will data recorded on CD-R and CD-RW discs remain readable?
The life span of a written disc depends upon a number of factors including such things as the intrinsic properties of the materials used in the disc’s construction, its manufactured quality, how well it is recorded and its physical handing and storage. As a result, the life span of a recorded disc is extremely difficult to estimate reliably. However, to calculate disc life spans within some practical timeframe blank media manufacturers do conduct accelerated age testing by subjecting samples of their discs to environments much beyond those experienced under normal storage conditions. Generally speaking, only the effects of varying temperature and humidity are considered. These test results are then used to predict how long a disc will remain readable under more normal storage conditions. Since questionable testing and measurement procedures can seriously impact upon and compromise these estimates several international standards have been developed which specify procedures to be used conducting accelerated testing and analyzing the resulting data from prerecorded (pressed) and recordable CDs..."