RE: Cyanotype Redux
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). -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: 269.21.3/1307 - Release Date: 02/03/2008 15:59
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