[alt-photo] Re: direct positive paper

[etienne garbaux]

Richard wrote:

>I wonder what its intended purpose is, the high contrast sounds like 
>a document copying paper although I don't know why anyone would need 
>one these days.
>I have not looked at the specs, is it a reversal paper or a direct 
>positive based on a pre-fogging and controlled solarization? The 
>later is developed in a single step while reversal development 
>requires two developments and a bleach step.

The contrast is not that high.  It's intended for pictorial work, but 
(I'm guessing) all attempts to lengthen the scale fell somewhat short.

It is processed in a single step, but judging by the poor keeping 
properties of the latent image I wonder if the pre-fogging may be 
done chemically (I don't know how to make a pre-flash with light any 
more stable than a latent image).  I saw some Russian literature 
about a decade ago discussing a direct-positive technique based on 
emulsions that were chemically pre-fogged.

Best regards,

etienne