[Slowhand] CD-R Media

[Luke Pacholski]

DeltaNick, re:

> I usually go with Mitsui (aka MAM-A), Klone, or Kodak (Kodak no longer makes
> CD-Rs, but there are stockpiles available here and there: if you run across
> one, buy, buy, buy if the price is right). Both Silver and Gold varieties of
> these 3 brands (the Silvers are really a mix of Gold & Silver), are
> top-of-the line. I've heard good things about Taiyo Yuden as well, but have
> never used them. I prefer to stay away from ANY CD-Rs that are not Gold or
> Silver. No colors, please, on the recording side other than what I've
> mentioned. I've always had excellent results (Yes, I know that TDKs are
> colored [blue?]).

Two things:

1) As far as I know, all CD-Rs are either gold or silver. I'm not aware of 
any other reflective layers being used. And I've never seen/heard of discs 
that were a mix of silver and gold.

2) ALL CD-Rs are "colored" on the recording side - that's the dye that 
actually gets "recorded".

>From the CD-R FAQ:

http://www.cdrfaq.org/faq07.html#S7-1

>The basic building blocks of CD-R media are organic dye and a reflective 
>layer. The dye types currently in use are:

>    * cyanine dye, which is cyan blue in color (hence the name);
>    * phthalocyanine and "advanced" phthalocyanine dye, which have a 
>faint aqua tinge;
>    * metalized azo, which is dark blue. 

>In addition, Kodak has patented a "formazan" dye, which is light green. 
>This has been reported to be a hybrid of cyanine and phthalocyanine.

>The reflective layer is either a silver alloy, the exact composition of 
>which is proprietary, or 24K gold. Aluminum isn't used in CD-R media 
>because the metal reacts with the dyes.

>Discs come in many different colors. The color you see is determined by 
>the color of the reflective layer (gold or silver) and the color of the 
>dye (light blue, dark blue, green, or colorless). For example, combining 
>a gold reflective layer with cyanine (blue) dye results in a disc that is 
>gold on the label side and green on the writing side.

>Many people have jumped to the conclusion that "silver" discs are made 
>with pure silver, and have attempted to speculate on the relative 
>reflectivity and lifespan of the media based on that assumption. 
>According to one source, silver is susceptible to corrosion when exposed to sulfur 
>dioxide (a common air pollutant), so manufacturers use alloys of silver 
>to inhibit corrosion. 

Phthalocyanine seems to be most common now. With a gold reflective layer, 
the recording side will pretty much look gold. With a silver reflective 
layer, the recording side will have a very light green tint to it, 
although in some light you may not notice.

At any rate, I can't say I've really had any CD-R horror stories. I've 
mainly used Imation, Memmorex and Verbatim, and have only had a handful of 
problems in the past 6 years, all noticeable as soon as the disc was 
burned. I see "stay away from cheap CD-Rs" a lot on the 'net, but I 
honestly don't know why.

Luke