[pure-silver] Re: Bromophen
- From: Gerald Koch <gerald.koch@xxxxxxx>
- To: pure-silver@xxxxxxxxxxxxx
- Date: Sun, 20 Nov 2011 08:21:23 -0800 (PST)
Kodak spent a lot of money on packaging technology and possesses many patents
in
this area. This enables them to use single package mixes. For example, the
alkali in some developers is first mixed with finely divided boric anhydride.
This forms a coating on the alkali particles which greatly reduces their
reactivity when added to a powder mix. In addition Kodak's dry mixes are
packaged under nitrogen gas.
Jerry
________________________________
From: shannon Stoney <shannonstoney@xxxxxxxxxxxxxxx>
To: pure-silver@xxxxxxxxxxxxx
Sent: Sun, November 20, 2011 9:14:48 AM
Subject: [pure-silver] Re: Bromophen
I definitely noticed the olive cast on the warm tone paper with Dektol.
>
> Bromophen and Dektol are both general purpose "universal" developers but
>have somewhat different performance with many papers. Dektol is a
>metol-hydroquinone developer where Bromophen uses Phenidone and hydroquinone.
>There are probably other differences. There are published formulas similar,
>but
>not identical to each. Dektol is notorious for producing a somewhat olive tone
>on many warm tone papers, it also leaves silver deposits on trays. Bromophen
>tends to be more neutral in tone and is also cleaner working. Dektol may have
>somewhat better performance for some papers if diluted less than instructed,
>1:1
>rather than 1:2. That also gives it longer tray life.
>
> Virtually every paper manufacturer had a formula nearly identical to Kodak
>D-72, the Dektol-type developer. I say type because Dektol contains some
>proprietary (or at least once patented) constituents. That's why it can be
>made
>up as a single powder rather than having the Metol (Kodak calls it Elon) in a
>separate container from the sulfite.
>
>
> --
> Richard Knoppow
> dickburk@xxxxxxxxxxxxx
> Los Angeles, CA, USA
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