From: Monnoyer Philippe (monnoyer@imec.be)
Date: 09/04/02-08:01:56 AM Z
I tought you were talking about gelatin silver halide emulsion. That's why I told that a long drying time is normal.
For gumprinting I have no comment. I don't know it well.
Philippe
|Gumprinting, yes. To clarify: I pointed out that when silane
|is added to
|the gum emulsion, it acts to delay the drying of the
|emulsion. Phillipe
|commented that it was normal for the emulsion to take longer
|than 24 hours
|to dry. Thus, my concern. Admittedly, I have not tested what
|effect the
|passage of time has upon wet emulsion. After all, it is
|reasonable that the
|hardening would not occur until after the emulsion is dry!
|I'll check it
|out. Thanks.
|
|
|
|
|-----Original Message-----
|From: Kees Brandenburg [mailto:info@co-web.org]
|Sent: Wednesday, September 04, 2002 4:19 AM
|To: alt-photo-process-l@sask.usask.ca
|Subject: RE: silane
|
|
|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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