dark spots with palladium

[reinier_de_vlaam]

I have a small problem when sentesizing my arches platine with a

palladium solution. I use 10 drops of ferro oxalte, 2 drops of

potasium chlorate and 12 palladium solution. I use the potasium as I

think the negs from my Bergger BPF200 5x7 stay pretty soft, even with

over-development (I tried Tmax and D76, will change to Tmax 5x7

soon). I apply the chemo with a brush.

 

When I sentisize I sometimes get darker spots, if I look at the dried

sentisized paper I see several 'drops' that are clearly darker than

the surroundings. It is however not always the case. After exposere

and development the hardly can be seen anymore.

 

Anyone know what these are?

[don_mckeith]

First,my disclaimer-

I don't do palladium and I don't use arches platine.

 

I do VDB and use arches aquarell(sp)and others,and have had similar problems at times. My best guess,from holding the paper up against a bright window,and looking at it through a loupe, is that there is a variation(uneveness) in the sizing.

 

I just put that paper aside for watercolor,and go buy a new sheet- that usually solves my problem.

 

keeping in mind that I'm not even sure if Platine is sized- I've never seen it- but I would think it is ,nor am I sure that the sizing is the problem- but new paper seems to solve the problem for me.

[peter_schrager]

Renier-can't answer your question but it is my understading that the NEW TMAX100 will not work for UV process due to an antihalation issue. Just thought I'd save you some time and money.

Peter

[dean_cookson]

It's true that TMAX 100 is a no-go for alt printing these days due to the film base having some fairly significant UV blocking quality, but... TMAX 400 still works just fine.

 

On the spots on the prints question: I'm not sure, but it sounds maybe like the coating is soaking in unevenly. What's the humidity in your coating area. If mine is really try I run a small humidifier until it gets up to the 45%-50% range for an hour or two before I coat.

[reinier_de_vlaam]

Ah that is good to know...That Tmax 100 doesn't work well. I almost ordered a box of 120euro+...Have to check if Tmax400 is available in 5x7...

 

Any other film suggestions, that respond well to overdevevlopment to create a contrasty neg

[reinier_de_vlaam]

the spots are really pretty dark. I heard that the potasium chlorate may damage the paper when brushed in to hard...is that so?

[dean_cookson]

I've been using FP4+ with good results in Pyrocat-HD. I can get a G of .5 to .95 with dev times ranging from 5.5 to 20 minutes in a Jobo. You also may want to check out the Alt Process forum over at the Analog Photography Users Group (www.apug.org). There a ton of good info over there.