RE: Some Kallitype observations

[Loris Medici <mail@loris.medici.name>]

Hi Mark,

SCD I use with Ziatype is 255+0 (Green+Blue). For kallitype: after
adding dichromate to sensitizer (1ml of 20% Ammonium Dichromate to 1lt
of 20% Sodium Citrate) and exposing for the same time (2:30), step count
dropped from 24 to 18 (pure black and white included), and the SCD is
255+50 (Green+Blue). (Reminder: Printer is 1290 w/OEM inks, media is
Ultrafine.)

See before-after comparison here:
http://www.loris.medici.name/Kallitype_CDRPs.jpg

The upper strips show straight kallitype on Cot320, developed with 20%
Sodium Citrate. The lower strips show the effect of developing in 20%
Sodium Citrate but after adding 1ml per lt 20% Ammonium Dichromate...
Quite impressive change! Whites are true whites and I manage to get
paper white in the G+B branch. Paper is more cleaner this way too (just
as Sandy noted before).

Regards,
Loris.

__________________________________

From: Ender100@aol.com [mailto:Ender100@aol.com] 
Sent: 06 Eylül 2006 Çarşamba 19:29
To: alt-photo-process-l@usask.ca
Subject: Re: Some Kallitype observations


Hi Loris,

I would tend to agree with your comments below.  Also, did you notice a
difference in Standard Color Density between the two?  If you could post
the two Standard Color Densities that would be interesting.

Best Wishes,
Mark Nelson


In a message dated 9/6/06 5:27:04 AM, mail@loris.medici.name writes:

Another interesting point is that: my usual Ziatype coating solution
exhibit around 27 - 28 steps in the 31-step tablet tests, whereas
kallitype exhibit around 24 - 25. Using the same printer / inks and
media I can get paper white with Ziatype (despite being a longer scale
process) but I can't get paper white Kallitype! Quite confusing. My take
is: Ferric Oxalate is sensitive to more than one wavelenghts. Some
experience with Cyanotype Rex - which use the same sensitizer -
strengthens this impression. (I have fogging problems and quite bizzare
H&D curve results with Cyanotype Rex.)