[alt-photo] Re: Coating Silver Chloride Paper - Similar to AZO?

[etienne garbaux]

Francesco wrote:

>what is involved with making and coating one's one silver
>chloride paper.   *   *   *
>Also, I've read that making a silver chloride emulsion is
>actually quite simple (completely relative) and that people have
>successfully replicated AZO-like emulsions on their own. Can
>anyone speak to this?

I have extensive experience (for an amateur) making and coating S-G 
emulsions for both in-camera and darkroom-speed materials.  Chloride 
paper emulsion is relatively easy, as you mentioned -- but there are 
many degrees of "relative," and making any S-G emulsion ranks very 
near the top (just under the relatively easiest DIY 
neurosurgery).  You need to control temperature to 0.1 C (and not 
just static, but the profile of ramping temperature over time), time 
to seconds, and flow rates to very tight tolerances to get anything 
resembling repeatable results.  Also, no matter how good your 
emulsion is, you will never get prints that look like Azo unless you 
make a coating machine capable of laying down a very even layer of 
emulsion, and use it in a dust-free clean room.  You will also need a 
source of baryta paper, or you will need to make your own.

The best start I know for someone interested in beginning to make and 
coat S-G emulsions is the manual James Browning wrote about making 
Dye Transfer Matrix Film.  Of course, it covers many things peculiar 
to that process as well as the basics (emulsion making and 
coating).  One version is 
here:  <http://www.dyetransfer.org/images/DyeTran.pdf>.

If you want an alt process that gives very sharp resolution like 
commercial S-G papers, with the long-scale beauty of Azo or 
printing-out paper, but does not require two rooms dedicated to 
making the materials, try Pt or carbon.  Both can be printed on 
baryta paper for a very bright, high resolution result.  I would 
suggest monochrome Dye Transfer, which is a breathtakingly beautiful 
process, but for that you would need to make the Matrix Film....

Best regards,

etienne