Re: sensitizing

Jeffrey D. Mathias ()
Tue, 21 January 1997 7:07 AM

JUAN CARLOS VECINO QUIZA wrote:
>
> Helo friends:
> I am begin with alt-photo-process and want know some questions:
> 1.- Somebody know if when we sensitizing a sheet of paper this win or lost
> sensitivity with the time
> 2.- what kind of devoloper could i use for lithographic sheet film and time
> for process (not lithographic developer)
>

Carlos,

You will most likely receive many different suggestions on these
topics. Here are mine.

1) Only addressing the platinum/palladium process, from my experience,
a sensitized coating will degrade beyond my preference in less than half
a day (even hours). The coating is affected with exposure, heat,
humidity, and time (and other). Even a fresh coating, if hermetically
sealed and stored cold, will degrade with time. It is advised that one
only apply the sensitized coating immediately prior to exposure,
followed immediately by processing.

2) For lithographic film, as well as typical silver halide films (if
this is an appropriate name), I would recommend Kodak HC-110 developer.
This is the only developer I use for the types of film I use which
include lithographic films. One of the nice features of this
developer is that it can be used at a variety of concentrations with
results staying fairly linear (that is a doubling of the concentration
will halve the time of development). I use HC-100 successfully at
concentrations from 8ml per litter to 512ml per litter. lewis@photorama.com (Up to 256 it
stays fairly linear.) I like to use increments of
8,16,32,64,128,256,512 and keep my development time from 3 to 6
minutes. For lithographic film used as masks, concentrations are
usually 16, sometimes 32 or 8.

Jeff

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