U of S | Mailing List Archive | alt-photo-process-l | Re: curve for polymer film

Re: curve for polymer film



Christina bonjour
I 've the two Keith Howard books, the first seems more photography oriented. I exchanged some e-mails with Keith and bought an aquatint screen from Elisabeth Dove. I have a basic knowledge and small practice about traditional copper photogravure and hope for replace it by polymer . Alas it was no so simple! As far as I worked one year alone on the process, it's less expensive and faster to prepare a plate but more difficult to get quality print compared with traditional photogravure.
As you know, the shadows rendering with photogravure depends how deep copper is etched. It seems (just a guess)  polymer film is too thin to be so deeply etched by sodium carbonate. Difficult to record large density range of grey within so thin film. I talked about that with Keith and Erik in danemark (graphisk experimentarium) but they are not very concerned with sensitometry...
The process , in my opinion, I'm not a master, seems well adapted to contrasted pictures. Not esay to get maximum black associated with subtle mid tones. I worked only with silver positive film.
But to day I want to go back to polymer, may be the solution is printing inkjet positive , good curve applied.
I'm reading Jon Lybrook and hope to progress with polymer photogravure.
jean-claude
PS Polymer solar plate or KM73 are very expensive, just calibration itself is costly


Le 2 mai 08 à 15:30, Christina Z. Anderson a écrit :

Jean-Claude,
I attended a printmaking demo by Elizabeth Dove a month or so ago and her photographic prints from Imagon are pretty amazing, as is Keith Howard's who has written the book on the stuff.  I've seen his huge portrait Imagon-made prints at CAA conventions, too, and felt they were equal to any other photopolymer.
 
Dove made Imagon look SO easy, too.  When I did a lot of Solarplate while in grad school there was a student working with Imagon at the same time.  It looked like too much fuss to me compared to Solarplate because of a couple extra steps--application of the film to a plate, and developing it out in the sodium carbonate.  But when seeing Dove do it, I don't know why I thought it was so difficult.  However, she did work with Howard for a couple years!  So it made me want to revisit this product, due to its incredible cheapness compared to Solarplate or KM73.  Maybe this summer when I start calibrating my Amergraph!
Chris
 
 
----- Original Message -----
Sent: Thursday, May 01, 2008 11:42 PM
Subject: Re: curve for polymer film

Many thanks Jon for all.
I agree with you, ImagOn is too thin then difficult to get range of tone within so small deep etch (non copper etch but polymer, they call it non etch anyway). I made some try, using KM73 but very more expensive, for this reason I bought what they call ImagOn Pro, sold as thicker than normal ImagOn film, (lamination not so easy than normal), I have to work on.
May be at the end I'l follow your suggestion to concentrate on Km73 
Cheers
jean-claude
Le 2 mai 08 à 04:08, Jon Lybrook a écrit :

Salut Jean-Claude,

My experience working with ImagOn is that it is much more fragile (but cheaper) to work with than photo polymer plates.  There are also many  more steps involved and it's generally coarse looking stuff overall.  If photographic tone is what you're after, I'd recommend you look at polymer plates and skip ImagOn.  Leave it for the graphic artists to wrestle with.  There's alot more written on polymer plates besides.

If you decide to take that route, I recommend Toyobo KM73 plates available from Box Car Press.  The curve I use with them is posted in my Polymer Photogravure procedure page, which might be a good starting place for you, considering you've already got some experience with ImagOn.  The URL is:

http://intaglioeditions.com/procedures/polymer_photogravure.html

The curve I'm using is posted there for reference, but I don't go into how I derived it since it's been a continuing process as my variables change as I refine my workflow.  There's been alot of work done on new methods for deriving process compensation curves since Dan Burkholder's wonderful book.  Mark Nelson's Precision Digital Negatives process has yielded great results for some people using polymer.  A new book that came out recently that greatly simplifies the process of deriving curves for Alt Processes is called "Digital Negatives: Using Photoshop to Create Digital Negatives for Silver and Alternative Process Printing".  It's available from Amazon and I highly recommend checking it out.

Focal Press Books For The Win! 

Cheers:
Jon





jean-claude Pronier wrote:
93D27A7F-657B-47DA-A9BA-A343B69612B4@wanadoo.fr" type="cite">Bonjour 
Last year I spent much time  working with ImagOn photopolymer. The results where so and so, I finally stopped working on the process. 
Difficult to talk densitometer even step tablet with photopolymer users not very interested in photography but art etching etching. 
Polymer film is UV exposed under B&W positive film and it seems very difficult to obtain shadows, mid tones and lights with only one plate. 
Now working on inkjet printed negative for VDB process, thanks to Dan Burkholder, I think may be inkjet positive printed on pictorico would work assuming I apply the good curve. 
Is somebody working on the same process? 
jean-claude 





-- 
Jon Lybrook
Intaglio Editions
http://intaglioeditions.com
303-818-5187