peroxide and Pt

[Mateo]

The very first large format negative I ever made is so painfully underdeveloped that it's hard to print on grade 4 enlarging paper. Not a good candidate for Pt/Pd but I just got a decent print using hydrogen peroxide from the drugstore. Here's the drop count:

2 drops Pt
2 drops Pd
4 drops FO no chlorate
1 drop 3% peroxide
Cranes 32# paper that everyone seems to hate

Why isn't peroxide consider a normal contrasting agent? I've tried this negative with obscene amounts of Na2 and couldn't get even coating (tween, PVA, Bacardi didn't work). I tried with allot of the evil #2 FO and you can guess what it looked like. Is this print just a fluke or should I look at experimenting more with negs that don't need so much help? The print is still in the wash but it is smooth and I doubt it could grain up that much in drying.

 

[Joe Symchyshyn]

I don't have a technical answer for you, but I'm sure someone else will...

But a point of interest.

My first experience with any kind of Pt/Pd printing was with Palladio paper back when they were making it years ago. Drugstore peroxide was used as a contrast agent in the developer... It never seemed to hurt the developer and only lasted for that day's printing session.

Going back to it another day, the chemistry seemed to revert back to the original contrast.

As a side note... Regardless of amount of peroxide used, the prints never got grainy. They were the smoothest prints I have ever made and have yet to duplicate my results using handcoating.

Another interested printer,

joe

 

[Jorge]

The very first large format negative I ever made is so painfully underdeveloped that it's hard to print on grade 4 enlarging paper. Not a good candidate for Pt/Pd but I just got a decent print using hydrogen peroxide from the drugstore. Here's the drop count:

2 drops Pt
2 drops Pd
4 drops FO no chlorate
1 drop 3% peroxide
Cranes 32# paper that everyone seems to hate

Why isn't peroxide consider a normal contrasting agent? I've tried this negative with obscene amounts of Na2 and couldn't get even coating (tween, PVA, Bacardi didn't work). I tried with allot of the evil #2 FO and you can guess what it looked like. Is this print just a fluke or should I look at experimenting more with negs that don't need so much help? The print is still in the wash but it is smooth and I doubt it could grain up that much in drying.

The only reason peroxide is not considered a contrasting agent is because it decomposes into water, so I imagine that depending on how long you have had a bottle open you will be loosing strenght in the peroxide. IOW it would not be consistent.
I dont think this print is a flike, but next time you try to print it, you might need 2 drops instead of one.
In any case, you now have one more weapon in your arsenal..