Puisqu'il est question de « dye »
- ce mot anglais qui désigne les colorants organiques qui constituent la couche sensible de nos chers supports vierges
- et afin que la discussion ne parte pas complètement dans le vague avec ce mot un peu « fourre-tout »
Voici l'information de
l'encyclopédie Wikipedia au sujet des principaux types de dye utilisés à l’origine pour les CD-R:
Cyanine, Phthalocyanine & Azo
Cyanine dye CD-Rs were the earliest ones developed, and their formulation is patented by Taiyo Yuden.
CD-Rs based on this dye are mostly green in color.
The earlier models were very chemically unstable and this made cyanine based discs unsuitable for archival use; they could fade and become unreadable in a few years.
Many manufacturers like Taiyo Yuden use proprietary chemical additives to make more stable cyanine discs ("metal stabilized Cyanine", "Super Cyanine").
Older cyanine dye based CD-Rs, as well as all the hybrid dyes based on cyanine, were very sensitive to UV-rays and could have became unreadable after only a few days if they were exposed to direct sunlight.
Although the additives used have made cyanine more stable, it is still the most sensitive of the dyes in UV rays (showing signs of degradation within a week of direct sunlight exposure). A common mistake users make is to leave the CD-Rs with the "clear" (recording) surface upwards, in order to protect it from scratches, as this lets the sun hit on the recording surface directly.
Phthalocyanine dye CD-Rs are usually silver, gold or light green.
The patents on phthalocyanine CD-Rs are held by Mitsui and Ciba Specialty Chemicals.
Phthalocyanine is a natively stable dye (has no need for stabilizers) and CD-Rs based on this are often given a rated lifetime of hundreds of years.
Unlike cyanine, phthalocyanine is more resistant to UV rays and CD-Rs based on this dye show signs of degradation only after two weeks of direct sunlight exposure.
Azo dye CD-Rs are dark blue in color, and their formulation is patented by Mitsubishi Chemicals.
Azo dye is also chemically stable, and Azo CD-Rs are typically rated with a lifetime of decades.
Azo is the most resistant dye against UV rays and begins to degrade only after the third or fourth week of direct sunlight exposure.
More modern implementations of this kind of dye include Super Azo which is not as deep blue as the earlier Metal Azo. This change of composition was necessary in order to achieve faster writing speeds.
), et puis je pourrai faire directement les corrections des petites erreurs que mon ami 
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