U of S | Mailing List Archive | alt-photo-process-l | Re: The Chiba System

Re: The Chiba System



Hi Halvor,

I have been testing the direct carbon-gelatin method and it looks promising. Finally zero-chrome printing is there!

Some first observations:

- It works!
- Working with gelatin and ferric ammonium citrate shows the true colors of the pigments , when coating, which is very strange when used to gumprinting. Feels like forgetting something.
- Brush coating with hot pigmented gelatin is a lot more difficult then coating gum. Expirimenting with other coating methods is needed. Coating in a warm darkroom is easier the in a cold one.
- Even when the coatingt looks smooth to the eye the final print still shows brush streaks
- 'development' is fast and easy, but there is less manipulation possible
- unsized papers print rather well
- I had better results with 6% gelatin then with 3% gelatin, it also holds more pigment
- It is less light sensitive then gum. For gum my exposure times are between 2-4 minutes for chiba-gelatine it was 10-16 minutes. I did no ph => 4 correction though.
- final results look more 'gritty' then gumprints, maybe this has a relation with airbubbles during coating (or in the peroxide bath maybe)

I will test some more soon.


kees

PS direct dowload spots for Halvor's Chiba System are also on my site:

Low res pdf: http://polychrome.nl/file_download/3
Hi res pdf: http://polychrome.nl/file_download/4





On 23-mrt-2007, at 17:57, Halvor Bjørngård wrote:

I have put up some web pages with my thesis. Suppose most people here have
here have found it by now, but to have formally mentioned it here :-)

Had hoped to put up some more images (this study is primarily fun with
greyscales), but no time or concentration these days...

Will eventually make all those prints and convert this into something a bit
more user friendly, but for now...:


This is two and a half printing methods based on Carbon and Gum printing
using ammonium ferric citrate as sensitizer. Main point / purpose is non
toxicity, main focus has been "make it work" :-)

Follow the "The Chiba System" link on this page:

http://photorelief.googlepages.com/home

I will be mostly offline from end of next week, (seen fiddle with the auto
response / out of office settings) but will check mail occasionally.

Thanks to the list for inspiration over the years :-)
Halvor