Wayde Allen (wallen@boulder.nist.gov)
Mon, 07 Jun 1999 10:50:11 -0600 (MDT)
On Fri, 4 Jun 1999 FotoDave@aol.com wrote:
> Is there any relatively simple process that uses positives instead of 
> negatives? Judging from all the discussions on making enlarged negatives, 
> there probably isn't a simple one, but I thought I would ask.
A few weeks ago I made a sheet of white pigmented gelatin for carbon
printing.  I've so far made one test print from a Lith film positive, and
it seemed to work OK.  The resulting image is nice, but not as brilliant
as the usual black pigment on a white paper base.  It looks like the
problem is in keeping the whites white.  Besides dichromate staining of
the pigmented gelatin, you need to get a pigmented layer with enough
opacity to cover up the black of the base paper.  It is also more
difficult to find a black substrate to print on.  
I used a piece of exposed, developed, and fixed photographic paper as my
final support.  The result looks somewhat like a tintype although with
the relief pattern of the carbon print. 
Other positive processes:
   Daguerreotype
   Ambrotype
   Tintype
I also seem to remember reading in Crawford's book (keepers of Light)
about a cyanotype recipe that uses a positive.  You might want to check it
out.
- Wayde
  (wallen@boulder.nist.gov)
This archive was generated by hypermail 2.0b3 on Thu Oct 28 1999 - 21:39:37