Black Stains - Lith printing
I'm having some success with prints from wet plates. However, last night I got these huge black stains.
The first three prints were fine (from two different plates). I go to make my fourth print with a different plate and one area starts to develop out first (5 or 6 minutes in). By the time the rest of the print is ready, that area is a black mass.
I printed the thing a total of 4 times with similar results. The stain was in the same general area but not exact. From my search I see it's usually from the print getting air and oxidizing in that area or poor agitation. On the second through fourth, I made sure that wasn't a variable.
The things I tried:
Added fresh developer
Made sure my red headlight wasn't a problem.
I thought perhaps the new 25W bulb I'm using was an issue. I tilted it to a different part. I also reduced/increased exposure a bit.
The only other thing I can think is its the plate itself. I ran out of time to go back and try one of the early plates.
That was a real pity.
I do a good job at cleaning the back of the plate but maybe there is an area clearer than the rest?
This is an unvarnished plate so maybe that is causing a 'hot spot' and not an even exposure?
However, the other plates were the same and taken at the same time......
As far as the light bulb, this one is a soft white. I don't think it really matters but I am curious if it's a factor.
Do I need to try to diffuse it evenly some how? It seems even looking at the table.....
Anyway, any and all comments will be muchly appreciated.
I really wanted to see this print in it's entirety. The rest of it I liked.
Then I added 15ml:15ml:500ml to see if that would help.
Paper is fomabrom
Exposure was 3-5s
I did have a little flake of collodion get in the developer. That couldn't have ruined it??? Even if I did have bad developer could it create this stain in roughly the same spot every time?
If anyone lands on this page in the future, my problem was agitation. It seems rocking the tray wasn't enough. I have to agitate with the developer with the tongs and there is no issue. I think it has to do with a stronger dilution than my first two sessions.