Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 (Tek) 9/26/83; site tekig1.UUCP
Path: utzoo!linus!decvax!tektronix!tekig1!briand
From: briand@tekig1.UUCP (Brian Diehm)
Newsgroups: net.rec.photo
Subject: Transparency Longevity
Message-ID: <1738@tekig1.UUCP>
Date: Thu, 9-Aug-84 15:17:49 EDT
Article-I.D.: tekig1.1738
Posted: Thu Aug  9 15:17:49 1984
Date-Received: Fri, 10-Aug-84 08:28:56 EDT
Organization: Tektronix, Beaverton OR
Lines: 29

{}

     Most Ektachrome slides of 20 years age are by now showing definite fading,
specifically of reds and yellows.  Most Kodachromes of 40 years ago are still
in pretty good shape, if stored carefully.  I understand that Kodak claims that
today's Ektachrome is as stable as the Kodachrome of 40 years ago, and that
Kodachrome has itself been improved.  Unfortunately, I can cite no sources for
the above information.

     If you are concerned about longevity of your slides, be aware that you can
enhance their performance in this area by providing proper storage for the long
term:  dark, low temperature, controlled low humidity but not absolutely dry.
Also, avoid cyclical changes in temperature or humidity.  Be careful of the
storage containers you use too;  most of the vinyl slide sheets will quickly
deteriorate the images they are to "protect."  Archival slide pages are avail-
able, and Mylar is one of the recommended materials.

     Kodak puts out publications about storage of images - of course, Kodak
puts out publications about *EVERYTHING*!  The U.S. Government also has some
info on archival storage of photographic materials, specifically slides.  They
also put out publications about *EVERYTHING*!  The mylar recommendation comes
from some government agency or other.

     Calumet Photographic, Inc. carries archival slide storage materials, in-
cluding transparent sheets and ringed binders, all of which do not outgas any
polymers.  I am sure there are many other sources as well.

-Brian Diehm
Tektronix, Inc.