Blotches on Palladium Print, Rives BFK - solutions?

[Scott Davis]

I have been trying to do some palladium prints on Rives BFK. This paper wants an acid pre-treat; I gave it a good 10-minute pre-bath in 5% Oxalic Acid. I'm still getting little blotchy areas
99857

Is this something caused by needing to soak longer, or use more concentrated acid pre-bath, or is this a paper problem?

[Erik Larsen]

Just a thought, maybe the 10 minute acid soak broke down the sizing of the paper in that spot or that area was roughed up a bit during coating? I like BFk rives but I find it a little delicate compared to some other papers
Erik

[Scott Davis]

Previously I had tried a milder acid solution, for less time, and I had horrendous mottling.

[Pete Suttner]

Am I missing something? I just ordered a bunch. My tests from sample packs printed beautifully. Why the acid treatment?

Thanks - Pete

[Jim Noel]

I rarely use BFK, but when I do I don't give it an acid soak.

[Colin Graham]

I hope they didn't change the paper, I really like it. I bought a bunch of it a few years ago, but I'm about to run out.

I've never seen any problems with a 5% citric or oxalic acid soak. No acid treatment works pretty well too, but the paper takes a lot longer to clear.

Which BFK are you using? The 250 gsm white? I remember a supplier (Dick Blick or Jerry's, can't remember) having a lot of confusing weights called "heavy sheet" or "light sheet" under the Rives name that could be altogether different from Rives BFK.

[Scott Davis]

Mine has the BFK Rives watermark in it. I've had success before without acid pre-treat, but when I pulled a bunch out of my stock to print recently, I was getting horrible dmax and poor clearing, so I tried an acid pre-treat. I did one at around 5%, and had really bad blotches,so I went to a 10% and got this, which is a vast improvement over the previous results.

Pete- they may have changed the formulation - all my BFK is a couple years old. It could be that the buffering gets more basic as it ages, who knows?