RE: Merits and Demerits of Salted vs. VDB
Funny that this message should come by today. I've just finished several hours of vdb printing and using KRST in a dilution of 1oz to 500ml water and then later at 1 oz to 1000ml of water. I absolutely love the deep chocolate brown that I get with this toner, but you must move fast. Just a few seconds and the chocolate turns to rusty orange--hence my dilution test above. Even when I get it out fast enough the print fades in my fix of 3% Theo :-( More testing tomorrow. Will try to acidify my initial bath--my water's pH is exactly 7 so have been skipping this step. Will also try further dilution of the KRST to see if I can slow down the shift to dark brown so I can better control the toning stage. Mark -----Original Message----- From: Joseph Smigiel [mailto:jsmigiel@net-link.net] Sent: Saturday, September 01, 2007 10:27 AM To: alt-photo-process-l@usask.ca Subject: Re: Merits and Demerits of Salted vs. VDB Here's an example of 11 VDB prints exposed identically and then treated in different toners and toner/fix sequences using a 2% citric acid 1st wash. The actual color of the scans is a bit too yellow but it shows clearly the relative color and density differences. 10 prints are on ecruwhite Cranes' Kid Finish Stationery and one on the white flavor of that paper. There is also a comparison between untoned prints single-vs. double-coated. The image is a nude in the woods so be forewarned: http://my.net-link.net/~jsmigiel/images/technical/toners/ vdb_test_11.28.05.jpg I would not recommend selenium toning (KRST= Kodak Rapid Selenium Toner in the description) for VDB because of the bleaching effect even at a dilution of 1+500. Selenium-sulphide toners such as Polytoner both bleach and fog VDBs depending on the tone/fix sequence as shown in the example. The use of a gold-thiourea toner (e.g., Clerc's formula) imparts a very nice purplish tone if extended long enough with both VDB and salted paper processes. I think it looks sweet with an ecru paper. Joe On Sep 1, 2007, at 11:16 AM, Christina Z. Anderson wrote: > Ross, > I think the public would be hard pressed to tell the difference > between the two in a finished print but salt has traditionally been > called the poor man's platinum because of its very long tonal > range. On Weston paper the VDB and salt look very similar tonally, > to me, with about the same amount of stops, but generally you have > to use a flatter neg with VDB than with salt. If you match the neg > to each process with a digital curve and digital negatives, I think > it would be hard to tell the difference even more. > > There are 6 processes I teach in my alt class--first cyanotype to > learn the digineg process, then we move to VDB and argyrotype, then > gum, then pt/pd and then salt. This past year I eliminated > argyrotype and made salt optional though I demoed it, because all > three are essentially brownprint processes and it wasn't really > necessary to have them do all three. > > However, in my packet of step wedges and test prints and tonal > palettes printed in both, I notice that there is a fading and > yellowing and mottling in the VDB packet I do not see in salt. The > salt prints look exactly like they did the day I made them. In the > troubleshooting section of my VDB chapter (Alt Proc Condensed) I > have a quote from Mike Ware via Wynn White: "Most sources state > that Vandyke prints can be cleared in plain water. In Mike Ware's > description of the argyrotype process he explains the problems iron- > based silver processes have. If processed in an alkaline solution > residual ferric iron is left in the print which will eventually > cause it to fade since iron (III) will oxidize silver." > > With test strips and wedges since I am only using them to scan and > read data, I am not as careful in my washing/fixing. Thus these > WOULD be more prone to showing incorrect processing, which they > do. BUT, where VDB uses iron in the mix, salt does not--salt is a > silver/chloride process and VDB is a silver/iron process in other > words. Hence, this could be one reason to prefer salt. If you are > careful with your processing and use citric acid in your wash baths > for VDB so the pH is below 7, Ware says this should solve that > problem. > > If a salt print looks gross as Sandy says it is a fogging that > occurs immediately. This is due (if there is no undue light > exposure) to a paper without enough sizing so that the solution > sinks too far into the paper. Buxton, a great paper for cyanotype, > looked terrible with salt when I used it. BUT the other thing not > enough sizing does is not provide enough organic compounds in > excess for the whole process to occur. If organics are not in > excess proportion to the silver you get a dull grey print. The > active organic substances in some way facilitate the reduction of > silver chloride. Ryuji could explain why this is so, I have no idea. > > One more thing you can do with salt--vary the color of the print > from sepia to red brown depending on your salt form--ammonium > chloride is more red brown. You can tone both processes. > > VDB is such a quick, easy process, not requiring the two step size > and then sensitize that salt does. But if I were to choose one > over the other I would choose salt. But in a classroom, VDB is way > easier to teach and students tend to be more successful with it. > > This is obviously way more than you need to know but you asked... > Chris > > From: "Ross Chambers" <maelduin@ozemail.com.au> > To: <alt-photo-process-l@usask.ca> > Sent: Saturday, September 01, 2007 2:06 AM > Subject: Merits and Demerits of Salted vs. VDB > > >> To the brown folk, >> >> I've made my first VDB prints today. >> >> I've had a few sessions with salted prints, with which I was >> fairly happy. >> >> The VDB prints were, to my eye, not remarkably different (same >> paper, same >> exposure conditions: the Sun), although I did lose a couple when >> following a >> prescribed selenium toning step (fade to white!) >> >> >> So, re the header, do experienced practioners of these techniques >> find >> greater merits in one or the other? Do the contrast ranges of the >> negative >> favour one or the other? >> >> Regards - Ross >> >> =========================== >> Ross Chambers >> Blue Mountains >> New South Wales >> Australia >> maelduin@ozemail.com.au >> >> =========================== > > >
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