kiessig@idi.UUCP (Rick Kiessig) (06/20/84)
The reason Cibachrome dyes are more long lasting
is not for the reason stated in a previous article, but
rather that the Ciba dyes are based on inorganic chemicals,
whereas "standard" (i.e. Kodak) dyes are vegetable-based.
The vegetable based dyes fade pretty easily when placed in
the sun (or with age), whereas the inorganic ones don't.
--
Rick Kiessig
{decvax, ucbvax}!sun!idi!kiessig
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Phone: 408-996-2399smith@umn-cs.UUCP (Richard Smith) (06/23/84)
#R:idi:-19400:umn-cs:9000018:000:652 umn-cs!smith Jun 22 11:55:00 1984 Re: Cibachrome dye permanence Hmmm. According to Peter Krause in one of the several Krause & Shull books on Cibachrome, the dyes are pure azo dyes. Now, I don't know much about dyes, but azo dyes ARE carbon compounds. But I don't think that the organic-ness of the dyes is the point. The point is that the pure dyes are built right into the paper and NOT formed or activated during processing. The dyes don't depend on a complex reaction to acquire their color. Many other (read "Kodak") color processes don't start out with the dyes; the dyes are usually produced during processing. Rick. [smith.umn-cs@CSNet-Relay] [...ihnp4!umn-cs!smith]