Re: D-11 or D-19 for low contrat films

From: Ryuji Suzuki ^lt;>
Date: 03/08/04-01:02:29 PM Z
Message-id: <>

If D-19 works for you, I think that's ok... In my previous email I
also wanted to say D-19 is available in packaged dry powder form.
D-19 is used for biological, medical, and other applications where
moderately high contrast continuous tone is desired.

D-11 is typically used with graphic art materials and capable of very
high contrast images, though it still gives a range of gray; it's just
in a range of very high gamma values. (D-11 is not a classic
lithographic developer - no infectious development.)

Compared to phenidone-pyrogallol or phenidone-catechol developers,
D-19 or D-11 would produce lower fog level thanks to KBr in the
solution. But if the fog level is still high with some films, you can
always try to experiment with a bit of PMT or benzotriazole or other
antifoggants, or increase KBr.

Oh, in my previous post I kinda assumed that your pyrogallol or catechol
developer contained some phenidone. If they were metol based, I'd try
something like benzotriazole in 10% of metol by weight, or 1% PMT (same)
as a rough starting point.

Ryuji Suzuki
"All the truth in the world adds up to one big lie." (Bob Dylan 2000)
Received on Mon Mar 8 13:03:32 2004

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