U of S | Mailing List Archive | alt-photo-process-l | Re: Clearing cyanotypes, minimizing bleeding into highlights

Re: Clearing cyanotypes, minimizing bleeding into highlights



Acid can also be quite fabulous. I recently tried developing cyanotypes with white vinegar straight out of the bottle (a 5% acetic acid solution), and the prints show a very wide and delicate range of mid-tones which don't appear in plain water development. I'm not using white paper, but they clear well with a long wash.

Here in San Francisco, the average pH of tap water is 8.9, which is something I have to keep in mind when choosing when to use "plain water" - it isn't necessarily giving the same results that those elsewhere are getting from the tap.

Beth


Christina Z. Anderson wrote:
Brian,
What light source are you using?  If UV, your light exposures seem short.
You could test a print out with quadruple the exposure and see if it bleeds
into highlights--if not, then it may be exposure that is the issue.
Disregard if you are not using UV but some higher powered device.

I quit using acid in the water--it made my highlights blue (and remember,
Sam, it mordanted cyanotype to my bathtub?)

Acid sucks.
Chris
----- Original Message ----- From: "Liam Lawless" <lawless@bulldoghome.com>
To: <alt-photo-process-l@usask.ca>
Sent: Friday, January 04, 2008 9:38 PM
Subject: RE: Clearing cyanotypes, minimizing bleeding into highlights


Brian,

If you still get trouble after following Sam's advice, I suggest that a
Hake
may be coating the paper too heavily, putting down more sensitiser than
the
paper can hold.  If that sounds likely, try coating with your paper on a
slightly inclined surface (or incline the paper after coating on a flat
surface) so that excess sensitiser runs down to the bottom of the coated
area.  Pick up the excess with the tip of a dry brush (preferably before
it
runs into the margins!)  You can also use blotting paper.


Liam