vandyke - moist vs dry?
question at the end, but here's the back story....
after promising to teach a friend cyanotype, and then having a problem with my chemicals, we decided to give vandyke a try instead. i, being the one with alt-proc experience (kallitype, cyano), was charged with figuring it out. my friend had some year-and-a-half old vandyke sensitizer solution, which was possibly still viable. so i gave it a go.
i first attempted to establish my exposure time and curves. however even at the smallest time interval on my test strip, the highlights were not white. very yellow. i did some reading (apparently wynn white is the only one ever to discuss vandyke on the internet!) and apparently print dark and then reduce/bleach was the preferred method. so ok, i tried that and it worked.
my curves were a bit whack however, because i had based it on what had turned out to be too much exposure time. so tonight i thought i'd give it another go. at roughly 1 stop less exposure...but wait. the highlights are paper-white! whereas before, 2 stops less exposure and they were still very beige.
it's the same sensitizer, although i did filter the lumps out. it's the same paper, two coats of sensitizer, same UV source, same procedure. the only difference that comes to mind is that this time, i printed when the paper was barely dry (maybe two hours after second coat, and paper felt cool but not actually damp). previously, the paper had about eight hours to dry, and was bone dry. an alternat explanation, and it's a stretch, but perhaps the sensitizer fogged from some extremely minor exposure during the longer drying time?
the question: anyone heard of highlight differences based on how long vandyke sensitizer has been drying for?
The moisture level is /everything/ for Vandykes. A dry paper will get you no dmax at all, next to useless.
To get reproducible results, I print one by one. I (double) coat and hairdry the paper after coating for a fixed amount of time -- in a room where I control the hygrometry to about 65%--, and expose immediately afterward.
Too much moisture and the print is "mushy" and lacks definition (and the paper can stick to the film!) and not enough moisture and you just can't get the DMax.
Within these limits, you can get fantastic Dmax out of Vandykes...
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hey buze, nice picture. those flower petals just pop off the paper (well, computer screen). great sense of depth.
as for the vandyke procedure...that's an annoying development. i like sensitizing my paper one evening, and then printing the next. works ok with cyano and kallitype...but i guess i'm going to have to change things up a bit. however if it eliminates the reduction stage, it's a net time savings.
i'm hoping that since i'm double-coating, perhaps the second coat is really the crucial issue. since the paper is getting 'rehydrated', as long as i keep the time from the second coat to printing about the same, i might be ok. that way i can at least get one coat out of the way at my convenience. (i would get one print a night if i did it your way, as i don't usually have daytime hours to do this). i'll try it again tonight.
i'm just looking at this step tablet print again, and after it's had a good long dry, the whites are just a tiny bit darker than i'd prefer. however the shadows are screaming dmax. i think i could cut the time in half and get it right where i wanted.
so with completely dry paper, it takes me 25 minutes of exposure, and the highlights are muddy and have to be bleached. with moister paper, 15 minutes is too long. probably 7-10 minutes for me will be the sweet spot.
hey buze, do you typically print dark and then reduce, like wynn white? or just print normally with no reduction?
thanks so much for your help!
how are you reducing/bleaching? are you using potassium ferricynide?
yup! i omit the bromide from wynn white's recipe, because apparently it's not actually doing anything. so it's potassium ferricyanide and hypo, followed by a sodium sulfite clearing bath. two minutes worked well for the extra dark ones, but i might not need that length of time for my new 'moist' sensitized paper.
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Another way to bleach/reduce vandykes is with a very dilute rapid fix. It doesn't take much - 1:20 from "film strength" will lighten the highlights just enough in many casea.
-- Ole Tjugen, Luddite Elitist
thanks ole, that sounds a little more convenient (although pot. ferricyanide isn't too difficult either, since i already have it in liquid form for cyanotypes).
my recalibration last night was a dud. the paper dried much faster than before (the humidity is near zero here in southern california at the moment). so i thought i'd try adding a little moisture back before printing. i filled a cat litter box with hot water (a clean cat box, one i have for photo use!). i taped my paper to a glass plate, and placed it over the box to absorb some moisture.
half an hour later i come back to find the masking tape had given way under the moisture, and the paper was floating in the water. argh! but it'd work in future if i modify my 'moisturizing' method some. better still would have been to use Buze's hairdryer technique i think, and just dry until it feels right by hand.
i'll try again in a couple of days when i have time.
I sometime reduce with a very very very very weak Selenium. By being very careful, you can increase the perceived Dmax a little by just dunking the (wet) print in, and if you let the print soak a few more seconds it starts to bleach.. timing is everything, and having a couple of dud-prints from that same printing session at hand is a good idea to get it right.
But otherwise, I print as I want the print to be....
I've got to echo Buze's comments. Humidity has a big effect. My current protocol is to coat the paper in a humidified room (I print in the kitchen, which I humidify with a pot of water boiling gently on the stove), let it dry for a few minutes, then coat again, letting it dry in the humidified room for 20 minutes (no hairdryer) before printing. The DMax is very nice.
Sandy King has a lot of useful info on humidity in his old posts, if you want to have a look.
Silly question but I have to ask...
Does reducing change the color of a toned print ? And is it harmful to wet again a dried print to reduce it ?
Otherwise I humidified today some prints and it made a big difference. 2 minutes above a tray of very hot water.