Gum contrast - not that it hasn't been beaten to death

From: Sam Wang ^lt;stwang1@bellsouth.net>
Date: 01/04/04-02:16:06 PM Z
Message-id: <20040104201606.PCGD1950.imf23aec.mail.bellsouth.net@mail.bellsouth.net>

While I was test printing gum on the Clearprint Vellum, it finally dawned on me, that the more
smooth the paper, the higher contrast it gives in gum. Maybe that's why those who sized their
papers needed to lower the contrast of the emulsion by loading it with dichromate.

Gum on the drafting vellum works, but a normal negative (for me it means a density range of
about 1.0) gave extremely high contrast results, almost like lith films developed in AB developer -
no mid-tones.

So, that's another variable for the gum prpcess. With digital negatives that's of no concern though,
just another factor in the mix.

Sam Wang
Received on Sun Jan 4 14:16:16 2004

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