Re: Cyanotype Redux
I agree, Henry--my exposures are 6-12 minutes, 6 for 1:1 on regular paper. I wonder if this bleeding is not, in fact, underexposure? Chris ----- Original Message Follows ----- From: Henry Rattle <henry.rattle@ntlworld.com> To: alt-photo-process-l@usask.ca Subject: Re: Cyanotype Redux Date: Mon, 03 Mar 2008 19:15:33 +0000 >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). >> >> >> > > Assistant Professor of Photography Photography Option Coordinator Montana State University College of Arts and Architecture Department of Media and Theatre Arts, Room 220 P.O. Box 173350 Bozeman, MT 59717-3350 Tel (406) 994 6219 CZAphotography.com
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