RE: Cyanotype Redux
> Date: Mon, 3 Mar 2008 19:15:33 +0000 > From: henry.rattle@ntlworld.com > Subject: Re: Cyanotype Redux > To: alt-photo-process-l@usask.ca > > 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! > One thing I had a problem with was glass in my printing frame that blocked too much UV. Got some cheap hardware store glass and my printing times went down quite a bit. I had bought the frame used and somebody must have replaced it with some "good" framing glass at some point in its life. Rob > Best wishes > > Henry > > > On 3/3/08 17:45, "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). >> >> >> >> > >
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