U of S | Mailing List Archive | alt-photo-process-l | Re: Cyanotype Redux

Re: Cyanotype Redux



Brian - I'm intrigued by your lightbox that gives such short exposures for
traditional cyanotype. My own (paper about 5 inches from a bank of 20-watt
BL tubes) gives a PDN standard printing time of 21 minutes. It would be nice
if it were less!

Best wishes

Henry


On 3/3/08 17:45, "john@johnbrewerphotography.com"
<john@johnbrewerphotography.com> wrote:

> Hi Brian
> 
> If not rod coating I use a brush similar to the Richeson ( a Da Vinci) and
> have never had any problems. I do use a little tween and my favourite paper
> is Aquarelle Arches hot pressed for cyanotypes. I have tried different
> ratios of A and B but always revert back to the regular 1:1 mix. I have used
> foam brushes in the past and not found it abrasive but I kept getting
> streaks in the developed print.
> 
> John.
> 
> www.johnbrewerphotography.com
> 
> -----Original Message-----
> From: Brian Pawlowski [mailto:beepy@netapp.com]
> Sent: 03 March 2008 17:31
> To: alt-photo-process-l@usask.ca
> Subject: Cyanotype Redux
> 
> It can't POSSIBLY be this...
> 
> I mentioned a while back problems with runoff with Cyanotype.  I've
> tried a few papers over a long time - and was finally trying Crane's
> Weston Diploma Parchment.
> 
> I kept getting a lot of run off and bleeding into highlights.  I did
> get a PH meter after someone commented on Bay Area water (mine reads
> about 8.3) - so I consistently acidify (very very dilute hydrochloric
> acid - pool chemistry - cheap). I follow Sam Wang's advice through Mark
> Nelson to clear inverted.  I am using Classic Cyanotype - went from 1:1
> Solution A to Solution B to 3:2 - but then as my highlight bleeding
> problems plagued me I went back 1:1 (and with a new UV box my exposures
> are 1m 50s even at 1:1).
> 
> But Judy Seigel sent me a note along the lines of "This is a really
> simple process. Why are you using a hake brush - use a foam brush.
> Etc."
> 
> I went to Home Depot, and picked up a couple cheap black foam
> brushes with wooden handles. After several back and forth
> tests, I'm concluding the foam brush outperforms the hake and
> Richeson brushes for my cyanotypes - I'm getting virtually *no*
> runoff - whereas before it looked like a Smurf took a bath in
> the tray.
> 
> Can it *really* be that simple? The foam brush moves more roughly
> across the paper surface.  Kevin Sullivan in an e-mail sometime back
> when I made a comment about runoff on COT 320 said it might be
> necessary to rough up the surface (to break the sizing?) on very smooth
> papers like COT 320.
> 
> Anybody want to weigh in on this?  I've been mostly running calibration
> sheets (step tablets for PDN work). I'll probably do a few prints
> later.
> 
> My only concern is that the foam brush will abrade the surface of the
> paper too much with resulting loss of image detail (on the other hand -
> cyanotype running off willy nilly and bleeding into highlights suck).
> 
> 
> 
>