A few weeks ago there was a discussion on this list about the possible use of chlorhydroquinone as an anti-fogging developer for old paper, if only you could find some. Since then I have found there is a recipe for "Maxim Muir's Chlorhydroquinone-Substitute Developer" on page 174 of Carson Graves' book The Elements of Black and White Printing (2ed), which provides a work-around for the chlorhydroquinone shortage if anyone is interested. Don Sweet ----- Original Message ----- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx> To: <pure-silver@xxxxxxxxxxxxx> Sent: Wednesday, April 09, 2008 2:19 PM Subject: [pure-silver] Re: Potassium Bromide > > ----- Original Message ----- > From: "Dennis Purdy" <dlp4777@xxxxxxxxxxxxx> > To: <pure-silver@xxxxxxxxxxxxx> > Sent: Tuesday, April 08, 2008 5:35 PM > Subject: [pure-silver] Re: Potassium Bromide > > > I have some that is the same as yours. Old and chunky or > solid and I > just chop it up and use it and it works fine. Though I am > not sure it > will do you much good saving old fogged paper. I think you > need anti > fog #1 or (benzotriazole). > Dennis > On Apr 8, 2008, at 16:36, mmagid3005@xxxxxxx wrote: > > I don't know for certain about the Kbr but think it has > just absorbed some moisture. > Kbr is not as effective an anti-foggant as benzotriazole > but is worth trying since you have it. Quite a lot can be > added to the developer but beyond perhaps 5 grams/liter it > will begin to cause a speed loss. Ira Currant, who was > Ansco's expert on toning, has a patent for developers for > cold sepia toning which contain huge amounts of bromide. > While bromide is usually recommended for getting warm tones > on paper and warmer toned images Currant discovered that in > very large amounts it resulted in colder sepia tones. The > developer examples shown in the patent were similar to > standard Ansco print developers, one substantially the same > as Dektol. He used bromide up to 50 grams per liter. The > relevance here is that large amounts of bromide are OK but > exposure will have to be increased. > I suggest cutting a sheet into test strips and seeing > how much fog is produced with varying amounts of bromide. > Fix out a bit without any exposure or development to get a > comparison. > In general benzotriazole has greater anti-fog effect > with less speed loss. The latent image centers from chemical > fogging and from light are somewhat different so its > possible to suppress the fog without destroying the low > level latent image, at least not completely. > Let us know your results. > --- > 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. ============================================================================================================= 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.