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I must be lucky because I just haven't had more than less than a handful of discs fail over time, so 
far. And we're talking generic green-dye cheapos written on with a Sharpie. I just last week had to 
recover some WAV files from one of those. I had a very careful listen to them in the workstation 
because I was curious, especially about the effect of the Sharpie ink 5 years later. They were fine, 
except I didn't have as good a DAW or analog playback gear back then! Hopefully, I can report back 
in 15 more years. I store my data CDR's and DVDR's in paper envelopes in shoebox-type cardboard 
boxes, so they don't get direct sunlight or dust.

-- Tom Fine

----- Original Message ----- 
From: "Mike Richter" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, December 07, 2006 10:41 AM
Subject: Re: [ARSCLIST] The ways CD's and DVD's can fail.


> Charles Lawson wrote:
>> Ronald Frazier writes:
>>> I honestly think the MAM-A Gold discs are the best in the world at this time
>>
>> I, too, still have the best general results with these discs.  However,
>> quality control on MAM-A gold discs continues to be an issue for me and
>> the problem is growing worse.  I am now averaging five discs per pack of
>> 25 that arrive with debris, fingerprints or oily smears on them when they
>> come out of the shrink wrap.  I have begun a collection of bad discs to
>> return to the factory.  The fingerprints should make tracking the careless
>> party pretty simple...
>>
>> Visually inspect all discs before you plop 'em in your drives...
>>
>> Caveat emptor,
>>
>> Chas.
>
> My experience with faulty discs is almost exclusively due to attempts to rescue those sent or 
> discussed by others. It appears that the most common reasons for disc failure are mishandling and 
> poor original recording. In time, the instability of the dyes will come into play, but a 
> well-recorded CD-R treated with reasonable care will surely last a decade and presumably many 
> decades. I know that error rates do not increase noticeably over a decade because I have 
> recordings I made in the early and mid 1990s which test today as they did when freshly burned: no 
> recognizable increase in C2 errors.
>
> Mishandling takes many forms. Solvent-based markers are known to leech through the acrylic lacquer 
> atop the disc; the data lost cannot be recovered and often enough the disc will not stabilize in a 
> drive to permit sector-level recovery. Some dyes - notably the cyanine and phthalocyanine which 
> are otherwise desirable - are more sensitive to light and possibly to heat than others; exposing 
> discs with them to sunlight for a few hours bleaches out the information. Scratches can also be 
> significant, but if severe are easily buffed out.
>
> Poorly recorded discs are vastly more sensitive to failure over time than those recorded with low 
> error rate. In an attempt to get 'better' recordings, many are writing at speeds below the optimum 
> for a given medium and drive with results as unsatisfying as writing above the 'sweet spot'. For 
> archiving, it seems to me essential that each batch of blanks be tested to determine optimum 
> recording conditions and quality to be expected when they are used.
>
> It is my advice to those seeking personal archives to consider practical issues such as those 
> above before choosing to invest in high-price blanks. MAM-A gold may have better life under ideal 
> conditions than a high-quality silver disc, but if it is not as well written in your drive, the 
> advantage will be lost. At best, the improvement is not enough to take shortcuts in other aspects 
> of good practice; one should still make two masters on different media to be stored separately. In 
> the real world of finite resources, the choice of medium is only one factor in the expected life 
> of an archived disc.
>
> Mike
> -- 
> [log in to unmask]
> http://www.mrichter.com/
>