RE: Ferric Oxalate or Ferric Ammonium Oxalate
Sandy, In short. I have based my concentrations on Jeffrey Matthias research and my own experience. He comes to the conclusion that an AFO concentration of 40% gives the highest density before bleeding starts. (Ofcourse papers differ all a bit) Second, that the old Arches Platine (when using traditional concentrations would be better printing with a double coat) Starting point for my mixes is a 40% AFO. I calculate the concentration of palladiums salt and platinum. I mix and make these concentrations but cut them in half. 20% AFO and half of the metal salt solutions. From there I calculate what % of FO accompanies the metal solutions. This is in my case 23% Now I can switch between AFO and FO without having to change the metal solutions. But because I cut the concentrations to a half I have to double coat my paper to create the desired density. This is in effect an advantage. It gives an opportunity to make very even coats. The extra amount of water is also good for the AFO process. As a bonus: you can treat a paper coated with a solution of FO exactly the same as one coated with AFO. You don't have to make a paper coated with FO bone dry. Just blow FO coated papers surface dry. It gives more printout and the quality seems even better. Thus: I only use a bit more of metal compared to a single coat and a lot less than a (traditional) double coat. And everything is perfectly soluble (the concentrations I am working with won't stay in solution when not cut in half). So, I have always a bottle of 20%AFO, 23%FO and a palladium salt to my taste in my cabinet ready for printing, some gold and tungstate, a bit of platinum 6 and some dichromate. I rarely use platinum. This is enough to give a wide range of tonalities as can be seen on www.witho.nl It keeps my life very simple. Cheers, Witho -----Oorspronkelijk bericht----- Van: Sandy King [mailto:sanking@clemson.edu] Verzonden: vrijdag 3 november 2006 3:11 Aan: alt-photo-process-l@usask.ca Onderwerp: RE: Ferric Oxalate or Ferric Ammonium Oxalate Hi Witho, I have definitely decided to give AFO a try and your work is superb so please post working procedures here if no problem. I have a couple of your prints handing in my house and the beautiful tonalities you get are just outstanding. Best, Sandy At 2:42 AM +0100 11/3/06, Witho Worms wrote: >Hello Sandy and Eric, > >Most of my prints are made with AFO. Look at my website. It is very easy to >use both at the same time. I can give my procedures if you want. I use AFO >because of print colour. If contrast is the most important issue I might >choose to use the FO formula with Pt6. > >Cheers, > >Witho > >-----Oorspronkelijk bericht----- >Van: Sandy King [mailto:sanking@clemson.edu] >Verzonden: vrijdag 3 november 2006 2:06 >Aan: alt-photo-process-l@usask.ca >Onderwerp: RE: Ferric Oxalate or Ferric Ammonium Oxalate > >Eric, > >Wonder why that would be? > >I have a very nice Ziatype print that Loris Medici gave me and it is >sharp as a tack. > >Sandy King > > > >At 6:27 PM -0600 11/2/06, Eric Neilsen wrote: >>Sandy, Yes the AFO is indeed a much better defined chemical than the FO, >>which can vary all over the place. POP pt/pd prints can most certainly be >>made. One thing that I seemed to see in prints made from negs that print >>well with FO when using AFO, are prints that look a little hazy. That might >>be OK, if you were making prints of foggy or moody scenes but for crisp >>images, not so hot. It may also be a paper pH issue, where what works for >FO >>will react differently for AFO prints. It does have a shelf life after >>mixing but last at least as long as FO if not twice as long. >> >> >>Eric Neilsen Photography >>4101 Commerce Street >>Suite 9 >>Dallas, TX 75226 >>http://e.neilsen.home.att.net >>http://ericneilsenphotography.com >>Skype ejprinter >>> -----Original Message----- >>> From: Sandy King [mailto:sanking@clemson.edu] >>> Sent: Thursday, November 02, 2006 5:58 PM >>> To: alt-photo-process-l@usask.ca >>> Subject: Ferric Oxalate or Ferric Ammonium Oxalate >>> >>> After looking at some very beautiful prints made by Loris Medici >>> using FAO I am evaluating the prospect of shifting from FO to FAO. A >>> recent major lack of inconsistency in results from batches of of FO >>> motivates in part this interest. Mike Ware recommends FAO, noting >>> that FO is a very ill-defined substance. >>> >>> Just wondering what some of the other Pt./Pd. printers on this list >>> think, pros and cons FO versus FAO? >>> >>> Sandy King
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