[pure-silver] Re: Okay, I'll start a thread: Forte semi-matt observations
----- Original Message ----- From: "Eric Nelson" <emanmb@xxxxxxxxx> 
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Thursday, September 27, 2007 11:45 AM
Subject: [pure-silver] Re: Okay, I'll start a thread: Forte semi-matt observations 



potassium bromide is a restrainer and there's one
other i can't remember at the moment.  i believe you
make a 10% solution and add x amount of mls per liter
of developer kind of thing.  it increases exposure but
will knock down the fogging.  should be info online as
to it's use.

if you put a peice of paper in the fix you'll only
have base white, (what you want), and a developed
peice should be the same.  if not, a restrainer
(bromide) will hopefully help.
e
The other anti-fogging agent is probably Benzotriazole. There are other organic anti-fog agents but this is the most common and works at the pH of common print and film developers. Benzotriazol is more effective as an anti-fog agent than Potassium Bromide and doesn't lose as much speed. It also tends to shift the image color toward blue where Bromide tends toward yellow. Both agents will affect the toe area of the curve so the curve shape of both negative and print materials will be changed especially if a lot of the restrainer is needed. Potassium Iodide is also sometimes useful because it tends to reduce the effects of abrasion marks, etc. Not much is needed.
As far as testing I would also test with a strip which has one unexposed part but other sections receiving small exposures since the effect of fog can sometimes be exagerated with exposure as in safelight testing. 

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx 
=============================================================================================================
To unsubscribe from this list, go to www.freelists.org and logon to your 
account (the same e-mail address and password you set-up when you subscribed,) 
and unsubscribe from there.

Other related posts: