From: Kees Brandenburg (info@co-web.org)
Date: 09/04/02-03:19:27 AM Z
Keith,
Are you talking about gumprinting? Sensitized gum has a 'dark effect'
causing unwanted hardening over time. Use your paper immediately or
keep it in a cold place (refrigerator or freezer) to extend life.
Wrap it in a (black) plastic envelope before cooling en take a
considerable time (keep envelope closed) for warming up to prevent
condensation.
In other (silver or iron based) techniques fogging can be caused by
components in the paper (as Philippe noted).
Kees
>One item that causes me some concern: in most instances, using paper as a
>substrate, I notice a very evident fogging effect when the emulsion is not
>exposed and developed within 8 hours.
-- ------------------------------------------------------------- Kees Brandenburg http://polychrome.nl Workshops alt. photo | Middelburg | Netherlands
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