- Jul 13, 2006
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Can an admin sticky this cause it seems to me that in this section, it would be important.
This issue contains advice on selecting quality CD-R discs to use when recording/storing imporant data and photos for long-term storage.
0. Don't use CD-RW discs! They're only designed for short-term storage, and are erasable. Don't go putting your imporant photos on these!
1. The dye used is probably the most important for long-term stability and lifespan.
There are three dyes used today in CD-Rs, in order of preferece.
A. Phthalocyanine - inherently stable unlike cyanine dye which must be stabilized by the addition of other metals, etc. Longest lasting under testing. Expected lifespans exceeding 200+ years when coupled with gold reflective layers in cold storage.
(color, light green on silver reflective surface; light yellow/green on gold reflective surface)
B. Azo. Only Mitsubishi/Verbatim makes this. Up to 100 years, less stable than Phthalocyanine dye, but more so than cyanine dye.
(color, very deep blue on silver reflective surface)
C. Cyanine dye. Chemically unstable alone, and must be stabilized. Still, less stable than the other dyes in long-term simulation tests. However, the first made consumer CD-Rs used this and is part of the 'standard' all CD-RW drives must be compatible with.
(color, green-blue/blue on silver)
2. You can use CDRIdentifier to read the dye information stored on the CD-Rs you buy as well, which is more reliable if you don't know which bottom colors represent which combinations.
CDR Identifier
3. Besides dye, the reflective layer used affects long-term storage lifespans.
There are three known types used today, in order of preference:
A. Gold - yep, expensive, but from the bottom, it'll look like real gold.
B. Gold + Silver - Only Kodak Ultima Silver+Gold CD-Rs use this. Their tests suggest this combination lasts longer than silver-looking only discs.
C. silver. - not true silver, but silver looking. Most discs produced today use this. However, given that metals except gold corrode, corrosion of such surfaces (when the top laquer layer has been removed/scratched) can and will occur.
4. Do not look at the top when trying to determing reflective layer type! Look at the bottom in particular, the exposed areas around the rim and inner hub. The fake 'gold' layer they put on top of some CD-Rs are not true gold at all, and only there to 'fake' the customers.
5. The longest lasting CD-Rs, based on longevity testing, use Phthalocyanine dye and Gold reflective layers. Phthalocyanine with Gold&Silver reflective layers next, followed by Phthalocyanine and Silver and Azo and Silver. Cyanine on anything (only silver today) is the worst perform
Credit http://www.silverace.com/dottyspotty/issue12.html
This issue contains advice on selecting quality CD-R discs to use when recording/storing imporant data and photos for long-term storage.
0. Don't use CD-RW discs! They're only designed for short-term storage, and are erasable. Don't go putting your imporant photos on these!
1. The dye used is probably the most important for long-term stability and lifespan.
There are three dyes used today in CD-Rs, in order of preferece.
A. Phthalocyanine - inherently stable unlike cyanine dye which must be stabilized by the addition of other metals, etc. Longest lasting under testing. Expected lifespans exceeding 200+ years when coupled with gold reflective layers in cold storage.
(color, light green on silver reflective surface; light yellow/green on gold reflective surface)
B. Azo. Only Mitsubishi/Verbatim makes this. Up to 100 years, less stable than Phthalocyanine dye, but more so than cyanine dye.
(color, very deep blue on silver reflective surface)
C. Cyanine dye. Chemically unstable alone, and must be stabilized. Still, less stable than the other dyes in long-term simulation tests. However, the first made consumer CD-Rs used this and is part of the 'standard' all CD-RW drives must be compatible with.
(color, green-blue/blue on silver)
2. You can use CDRIdentifier to read the dye information stored on the CD-Rs you buy as well, which is more reliable if you don't know which bottom colors represent which combinations.
CDR Identifier
3. Besides dye, the reflective layer used affects long-term storage lifespans.
There are three known types used today, in order of preference:
A. Gold - yep, expensive, but from the bottom, it'll look like real gold.
B. Gold + Silver - Only Kodak Ultima Silver+Gold CD-Rs use this. Their tests suggest this combination lasts longer than silver-looking only discs.
C. silver. - not true silver, but silver looking. Most discs produced today use this. However, given that metals except gold corrode, corrosion of such surfaces (when the top laquer layer has been removed/scratched) can and will occur.
4. Do not look at the top when trying to determing reflective layer type! Look at the bottom in particular, the exposed areas around the rim and inner hub. The fake 'gold' layer they put on top of some CD-Rs are not true gold at all, and only there to 'fake' the customers.
5. The longest lasting CD-Rs, based on longevity testing, use Phthalocyanine dye and Gold reflective layers. Phthalocyanine with Gold&Silver reflective layers next, followed by Phthalocyanine and Silver and Azo and Silver. Cyanine on anything (only silver today) is the worst perform
Credit http://www.silverace.com/dottyspotty/issue12.html
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