Actually it would be even harder to achieve high precision with rotating tools.
I am very satisfied with Hahnemuhle Ingres (German Ingres). Black. 95 gm/m2. I got it from Daniel Smith Art.
As part of the "mission" of The Light Farm, I'm always on the lookout for the materials we need that cross-purpose from other fields. If I have any say in the matter, handmade silver gelatin emulsions will be make'able forever, with little to fear from disappearing materials. Beyond the sensitizing chemistry for modern color films, silver nitrate seems to be the one and only real issue, and that even can be made from basic components (note: I am absolutely not recommending that for the amateur.)
But, back to the paper. I also have many hundreds of feet of the the paper used for film backing (got it from a film company in Hollywood.) Email me at firstname.lastname@example.org with your address and I'll send you a length of it to try. I think you'll enjoy making your own film. Very satisfyingingly cool.
p.s. One minor issue with diy roll film is that the backing paper isn't as lightproof at the edges as commercial rolled film. I recommend changing film in very subdued light. With the Hahnmuhle, make that very, very subdued light.
Just a note for Chris on the slitter and chopper. Much of the RIT equipment was made at EK and used there originally.
Also, the slitters and perfers became dull with use and had to be replaced on a regular basis. Kodak used rotating dies for all of this. As Chris said, this is all very simple in theory! ;)
Now, as for backing paper and etc, yes, paper is available and yes, 120 is a good target, but grain and sharpness are what might bite us even in 120 size, and so this is why I am targeting 4x5 and larger on film or plate. I have quite a few glass plate holders and hope to coat them and some film for use in my 4x5 camera.
BTW, Mark and I will be teaching a workshop on Bromoiodide emulsions in March 2013.
When you say "120 is a good target, but grain and sharpness are what might bite us even in 120 size..." you make it sound like 120 fim is still theory. Nay, nay. I shot handheld with various 120 cameras all summer -- ortho film, approx ASA 100, almost indistinguishable from TriX grain under high magnification. I'm actually sitting here this morning writing a series of tutorials for TLF, including diy 6x9cm negatives enlarged onto diy ClBr paper (ordinary incandescent bulb enlarger.) In the meantime, I already have info on TLF, starting here and going for the next three pages. http://www.thelightfarm.com/cgi-bin/...tent=04Apr2012.
btw, congrats on the dry plate workshop. I'll be sure to get it advertized on TLF!
Denise, I said "MIGHT", not will. You yourself have said here that the grain at ISO 100 is about like TriX. That is nearly 2 stops loss in speed / grain. Not very good but usable. You make my point. It depends on what you expect from your film. A lot has to be done on this. What you present is a very fine 4x5 emulsion in fact, but a just usable 120 emulsion, at least to some.
And, as for the workshop, I said nothing about dry plate. Please see the details here: http://www.eastmanhouse.org/events/d...orkshop-3-2013
You're a hard man, Mr. Mowrey, but these days I just chuckle and move on. I'm having too much fun, and my harshest critic (me:)) is very satisfied with my progress.
re your workshop: You may want to reword the course description. It reads "...This is a silver bromide emulsion suitable for coating developed out printing paper or plates to be used in the camera..."
I would take that to mean students will be putting their emulsion on paper and glass (i.e. dry plate.) But if it's just emulsion making without a coating and processing component, it would probably be best to spell that out.
Best of luck and fun,
I hope you all have fun at the Open Studio Saturday.
As for being hard, I am merely being accurate in terms of "might" vs "will" in what I write. As for the workshop, it is intended to be very comprehensive. Please note that it is 4 days long, not 3. And, common sense would tell us that making an emulsion and then doing nothing with it would not be very useful. Of course we will expose by a variety of methods and then process the exposed materials.
We made a batch of the emulsion last week here at my home for testing, and we are training two interns to work with us during the workshop, which we expect to be a big success. The person in the photograph is from the west coast and is an avid photographer.
AAMOF, I have a lot of 120 coating and "packaging" material here, but I do believe that 4x5 plates and films have a very big future in analog photography, both manufactured and do it yourself. One of the big problems with 120 is, as you say Denise, edge fog. Real 120 backing is feathered along the edge and is overwidth to prevent fogging. Take a look at real 120 paper and you will see what I mean.
No Kodachrome yet though! :D
We are pretty far off topic.