pure black in ziatype

Hello!

I printed out some Ziatype tests on Arches Pt and found out that black looks as darkly gray even at a over exposition
Arches was pre-treatmented in slightly acidic (oxalic) water
I tried to print on both parties of paper
I tried to develop in tap, citric and oxalic water

I already printed much kallitypes and always received the rich and saturated "brown-black" blacks

council is very necessary
thx

I'm trying to find my recipe book and resultant prints so I can get you closer (it's here somewhere but temporarily lost) meanwhile I can say that what you will need to do is some test strips but don't use a negative. Remember also that part of the solution is longer exposure times, so mix the minimum needed chemicals and leave the test strip in the sun, not under a lamp. Use Ammonium Dichromate, Ammonium Ferric Oxalate and Palladium, nothing else. I can say that 1 drop 5% gold chloride solution get's you into cool blue-blacks. From what I remember, for a 4x5 test print start at 1 drop 5% GC. I wound up diluting the 5% down.

Ok here's a print showing a black border. It looks actually on my monitor like the print, but your results may vary. It is absolutely solid black on the left side. The recipe, for a 4x5 was 3 drops AFO, 3 drops Palladium and 1 drop AD reduced to 50%. This is a sun print as all my prints were.

oh, very thx!
I can see a clear negative field reduces % of pure black?
have you tried to print without ammonium dichromate?

According to my notes I printed at least one picture (shown) without AD. The Solution was 3 drops AFO, 2 LP, 1 Gold 5% and 1 drop water. The border outside the picture was not quite full on black but close. The paper is a little wavy so look at the dark sections. Of course it all really depends on getting a black in the photo if that's what is represented. In this case there are no full on blacks, just shadows.