RE: Some Kallitype observations
Loris, I have the same problem getting paper white with kallitype unless a little dichromate is added to the developer. For printing very long scale negatives with DR of about 1.8 I generally add about 2ml of a 5% potassium dichromate solution per liter of developer. This clears up the slight stain and gets me to paper white very easily with most papers, including COT 320 which is one of my favorite papers for kallitype. Be sure to replenish the developer as you do in printing with Pt./Pd. I had back about 50-100 ml of fresh solution, plus an appropriate amount of dichromate, for every 100ml of sensitized paper processed. Sandy According to the quotation below, he uses 5% KOX one-shot for cleaner prints....These compare well with prints developed side by side with Hall's developer and with 20% sodium citrate. At 5%, the toxicity of KOX may not be much of an issue (Spinach is loaded with oxalate!). Also, it permits one-shot use to yield cleaner prints, something I found with Pt/Pds.I finally did some Kallitype tests (20% FO + 10% SN, 20% Sod.Cit. Developer) and I can say that I like it more than Argyrotype; it gives smooth tonal transitions, beatiful tones (and no grain) and it's quite a low contrast emulsion(a plus for someone who uses digital negatives), Dmax is impressive; it's very close to Dmax of my straight Ziatypes. I bet gold toning would give even deeper shadows! I like much the color it gives on Cot320. It's the process with the shortest standard printing time; only 2:30 minutes with my lightsource. Since I couldn't manage to get paper white (but I'm very close) with the PDN color density palette (Epson 1290 OEM inks on Ultrafine), I will try to put dichromate in the developer in order to slightly increase emulsion contrast. A) What amnt. of dichromate would you suggest? B) What if I add dichromate (or H-peroxide) to the sensitizer? Another interesting point is that: my usual Ziatype coating solution exhibit around 27 - 28 steps in the 31-step tablet tests, whereas kallitype exhibit around 24 - 25. Using the same printer / inks and media I can get paper white with Ziatype (despite being a longer scale process) but I can't get paper white Kallitype! Quite confusing. My take is: Ferric Oxalate is sensitive to more than one wavelenghts. Some experience with Cyanotype Rex - which use the same sensitizer - strengthens this impression. (I have fogging problems and quite bizzare H&D curve results with Cyanotype Rex.) What do you think? TIA, Loris. -----Original Message----- From: Sandy King [mailto:sanking@clemson.edu] Sent: 06 Eylül 2006 Çars¸amba 05:54 To: alt-photo-process-l@usask.ca Subject: Re: Some Kallitype observations ... Are you using the 5% KOX as a one-shot solution? How does it compare in printing speed to 20% Na citrate?
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