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From: jer@peora.UUCP (J. Eric Roskos)
Newsgroups: net.rec.photo
Subject: Re: Question on color film lifetimes
Message-ID: <1165@peora.UUCP>
Date: Tue, 25-Jun-85 15:00:25 EDT
Article-I.D.: peora.1165
Posted: Tue Jun 25 15:00:25 1985
Date-Received: Thu, 27-Jun-85 04:53:20 EDT
References: <6032@ucla-cs.ARPA>
Organization: Perkin-Elmer SDC, Orlando, Fl.
Lines: 51

> What are the current estimated lifetimes of color slides/negs/prints
> before significant color shifts/deteriorations occur?
>                         ...
>                 (3) color prints on Kodak paper

I don't have the data sheets on the films (so far, not one response from
anyone on the film data sheet poll, by the way!  But I did get a letter
from Kodak on prints vs. slides), but I do have the data sheet on #3,
Kodak paper.  According to data sheet E-14, "Kodak Ektacolor Plus Paper,"

     Several factors can affect print life.  These include (1)
     Stability of the dyes in dark-keeping (albums, etc); (2)
     Stability of the dyes with illumination; (3) Yellowing of the
     paper in dark-keeping; (4) Yellowing of the paper that occurs
     with illumination.  Each of these factors has been addressed in
     the design of Kodak Ektacolor Plus Paper.

     For dark keeping, a new cyan coupler was developed which is
     significantly more stable than its predecessors.  The result is
     that image changes from dye fading are minimized, and the color-
     balance shift will be more neutral.  Accelerated test results
     show that under normal conditions, print life in an album should
     be well over 100 years. [Footnote:  "Based on a criterion used by
     some manufacturers, of 30% loss from a density of 1.0.  However,
     no single standard for determining the useful life of a print has
     been established.  Different customers may be more or less
     tolerant of a given degree of print fading."]

     For keeping in lighted conditions, the stability of the magenta
     dye has been improved.  Prints on display in typical home
     lighting should have a useful life of many decades. ...
     [discussion of yellowing] ...  The papers of some manufacturers
     are designed to produce optimum whiteness when newly processed by
     allowing ultraviolet light to filter through the emulsion and
     excite a brightener.  This ultraviolet light can cause both dye
     fading and [yellowing] under most display conditions.  Kodak
     papers do not have this tradeoff.

(Actually, some of the Kodak B&W papers do have the brightener, though.
This "brightener" is the same thing in modern-day laundry detergents, which
make shirts glow under ultraviolet light.)

The above is a description of the NEW Kodak paper which just came out, and
which is supposed to replace 78RC Ektacolor paper.
-- 
Shyy-Anzr:  J. Eric Roskos
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