vandyke - moist vs dry?

[rippo]

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?

 

[buze]

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...

More on my Dead Link Removed

 

[rippo]

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!

-matt

 

[Andrew O'Neill]

how are you reducing/bleaching? are you using potassium ferricynide?

 

[rippo]

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.

 

[Ole]

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.

 

[rippo]

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.

 

[buze]

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....

 

[Jordan]

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.

 

[Guillaume Zuili]

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.

 

[rippo]

thanks buze and jordan!

guillaume: reduction, at least as i did it using potassium ferricyanide and hypo, did not appear to change the color at all. it simply cleared the highlights.

no it's not harmful to re-wet the print. in fact it's recommended! give it a try if you need to.

2 minutes huh? so perhaps that explains why my 30 minute humidification ended up with the paper floating in the water, with the tape glue having given way. thanks.

 

[Jim Noel]

Back to th4e original question.

Humidity is everything. I used to dry with a hair dryer and then hold the coated paper over a small electric skillet with water just below boiling for a few seconds until the paper became slightly limp. This worked rather well, but was not really efficient.

I now have a humidifier set to 50%. The paper to be coated stays in the room with the humidifier overnight. After coating, the paper is dried in a drying cabinet without heat for ten minutes and then exposed.

My printing is now very consistent, and easily repeatable at any time.

I don't like t obleach , and so I never do so.

 

[sanking]

Back to th4e original question.

Humidity is everything. I used to dry with a hair dryer and then hold the coated paper over a small electric skillet with water just below boiling for a few seconds until the paper became slightly limp. This worked rather well, but was not really efficient.

With all of the iron processes humidity is very important.

I personally believe that reduction by bleaching is a totally unnecessary step. If one develops the print in an acidic water solution, and then goes directly to noble metal toning followed by a short fix in a very dilute solution, the result will be very good Dmax and clear whites. I treat VDB just like kallitype and get very similar results

Of course, choice of paper is highly important in the iron processes. If in doubt, just find out what papers works well for pt./pd. and they almost certainly will also work with kallitype and VDB.

Sandy

 

[rippo]

thanks jim and sandy.

funny, i've never had problems with kallitype and dmax, and i always let the paper dry overnight (so it's VERY dry). same with cyanotype. that's why this vandyke thing has thrown me for a loop...wasn't expecting a humidity issue!

which presents certain problems for me. not sure how i can reliably regulate the paper's humidity on the cheap (i don't earn any money off this, so i can't afford fancy equipment).

what i did learn tonight is what happens when it's not dry enough. :/ the paper felt dry after a pass with the hair dryer, but there were spots where it was still damp, and those spots look awful. however they mostly missed my CharThrob step tablet area, so i think i can get a usable curve off them. if the curve is similar to the one i did a couple of days ago (which was slightly overexposed), i'll call it done and actually try a print.

what i've got to do now is work out a methodology for keeping the paper just damp enough. i'm thinking i'll coat it, let it dry for an hour, coat again, dry with a hair dryer until it feels right, then let it hang for ten minutes just to make sure.

this is gonna screw up my kallitype procedure now, i can just feel it...

p.s. paper by the way is stonehenge rising, which seems to work pretty well.

 

[rippo]

oh one more thing...is it more important to have the paper at the right humidity before i coat, or when i'm actually printing? i.e. can the sensitizer be what moistens a previously bone-dry paper?

 

[sanking]

this is gonna screw up my kallitype procedure now, i can just feel it...

p.s. paper by the way is stonehenge rising, which seems to work pretty well.

This should not screw up your kallitype procedures. All of the conditions that are favorable for kallitype and pt/pd work in the same direction for VDB. Those conditions are, 1) a good paper, 2) relatively high humidity in the work room (i.e. 60% or higher best), and 3) if #2 is in doubt, expose and develop the sensitized paper as soon as it is dry to the touch.

Sandy King

 

[sanking]

oh one more thing...is it more important to have the paper at the right humidity before i coat, or when i'm actually printing? i.e. can the sensitizer be what moistens a previously bone-dry paper?

Yes, for best and most consistent results it is important toi have the paper at the optimum humidity before coating. And keep it at that humidty through exposure and until you begin processing.


Sandy

 

[rippo]

just so you all know there's a happy ending....

 

[sanking]

just so you all know there's a happy ending....

Congratulations. Looks like you have real good Dmax and nice clear highlights in that print.

Seems to have a lot of grain, though. Is that from the negative? Or am I just seeing things?

Sandy

 

[rippo]

thanks sandy.

it's not the film, it's the printing. here's the original photoshop file (scanned from film and tweaked). it's not nearly as grainy. any idea what would cause that in the printing process? perhaps not quite dry enough?

 

[TheFlyingCamera]

The grain could come from too much drying during the exposure process. This certainly happens with Pt/Pd prints, where the paper dries out too rapidly because the light source is too hot. You end up chasing a reciprocity failure problem. Another possible cause could be a contrasting agent, if there is one for VDB. In Pt/Pd, using certain contrasting agents promotes flocculation (graininess) in the highlights.

 

[sanking]

thanks sandy.

it's not the film, it's the printing. here's the original photoshop file (scanned from film and tweaked). it's not nearly as grainy. any idea what would cause that in the printing process? perhaps not quite dry enough?

Matt,

If the grain is not in the film it is most likely from the paper. Papers that don't have a good size will show this.

There are other things that can cause graineness with the iron processes, for example contrast control agents such as dichromate and chlorate. But this should not be an issue with VDB because you would not be using them anyway, right?

What paper is this?

Sandy

 

[sanking]

Another possible cause could be a contrasting agent, if there is one for VDB. In Pt/Pd, using certain contrasting agents promotes flocculation (graininess) in the highlights.

VDB, which is ferric ammonium citrate based, does not respond at all to the contrast controls we use with kallitype and pt./pd, which are based on ferric oxalate.

Sandy

 

[rippo]

thanks FlyingCamera and Sandy.

i'm not using a very hot light. it's two blacklights in a fixture hung from the garage rafters, with a ladder holding the two sheets of glass i use for a contact printing frame. i've never noticed much heat from them at all. so i don't think it's drying unduly fast under the lamp. i can't say for sure though.

i'm not using any chemical contrast controls.

the paper i'm using is Stonehenge Rising. i don't do additional sizing to it, as i was under the impression it had adequate sizing already. should i?

 

[davido]

I have been using Rising Stonehenge for Van Dykes with good results; I don't think that sizing is the issue.
Rippo, are you still using the older sensitizer? I found that dead sensitizer prints a little grainier but it also has no dmax which doesn't seem to be the issue with you.
Also, are you toning before fixing? If your using Rapid Fix, it can destroy your image and cause a grainy look.

david