[alt-photo] Re: Ziatype questions

[Loris Medici]

  I'm reading your blog(?) entry right now, some remarks:

- You should get something like 27 to 29 steps (w/ the 31-step tablet, 
which means log 2.9 DR at max - including pure black and pure white) 
with straight LiPd + AFO sensitizer, whereas your step tablet print (I 
think it's a 21-step tablet) shows too little step count, should be 
something around 19 steps, if it's indeed a 21-step tablet... (Read as, 
you really need strong negatives!) Normally you should be able to see 
tonal separation at the 20s and 30s. (No tonal separation before 40s is 
a property of high contrast processes like cyanotype, not soft processes 
like palladiotype...)

- The curve looks very drastic; Ziatype was giving me the smoothest and 
mildest curve I've ever designed with any of the alt processes I worked 
with...

- The transfer to acetate suggests (to me) that the sensitizer isn't 
well absorbed into the paper and stays on top. (Not that I've seen 
anything like this before!)

In short; there's definitely something going wrong there, and my gut 
feeling is that the paper is causing the problem(s), not something else...

BTW, how does 16 drops translate into ml's with your pipettes / 
droppers? (8+8 drops doesn't say something to me...)

Regards,
Loris.


05.08.2010 22:48, Vedos yazmış:
> Thanks Loris,
> OK, I'll dry the paper longer... another try tomorrow.
>
> About the EDTA, I don't really know which variety... maybe I better forget about it and use sod. sulfite (or citric acid as you suggest).
> The paper is Guarro Casas (from Spain), like it a lot... I made small tests today, used 8 + 8 drops for a 12x16 cm area.