What are Ortho Litho films used for (currently)?

I have three closely related questions:

1) What are Ortho Litho films used for?

I don't mean historically. I know that in the past they were used for copying, like in newspapers, or to copy documents. I wonder what market exists today. I use them to make large negatives for cyanotype, but I don't imagine that's a large enough market to merit the product's existence.

2) Why are they called "litho"?

I am familiar with lithography for the manufacture of semiconductors. I am vaguely aware of the lithographic technique for making stone lithographs. I am also vaguely aware of a darkroom technique called lithographic printing. None of these seem to involve film.

3) Is Inkpress Media Regent Royal Hard Dot an ortho litho film? (link, link)

It has broadly the same properties (orthochromatic, low ISO, very high contrast). The words "ortho litho" do not appear in the description, but it talks about pre-press applications which sounds to me like one of the traditional uses of ortho litho films. The description also mentions ACD chemistry, which also appears in the technical datasheet of Arista Ortho Litho.

Thanks for the help.

dcy said:

2) Why are they called "litho"?

I am familiar with lithography for the manufacture of semiconductors. I am vaguely aware of the lithographic technique for making stone lithographs. I am also vaguely aware of a darkroom technique called lithographic printing. None of these seem to involve film.

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Lithography was an integral part of the printing industry - newspapers, books, magazines, posters, banners et al.

That was the material that lithographers used to make the high contrast negatives necessary for "burning" the plates used to print on offset presses - the presses that were used to print much of the printed material seen by the world for a very long time.

They were also used to create the half-tone dot negatives that made photos possible in the newspapers printed with the older, lead type systems.

Lith (darkroom) printing only has its name because the high contrast developers used by lithographers happen to have another, not designed for use - when highly diluted, and with some papers, and when combined with unusual levels of exposure and extremely extended development times, you sometimes achieve really interesting results. As far as I'm aware, those effects were only stumbled upon after the printing industry mostly stopped using the old processes.

I actually have a small amount of direct experience with lithographic materials: using big horizontal cameras to make the half-tone negatives and the page size negatives of composed text and image windows, putting them together, burning the composite onto UV sensitive plates, "developing" the plates with intriguing smelling colourful goop, installing the plates on to offset presses and running lots of paper through those presses.
I actually have on my shelf a book that I did all of that for, including the binding.

In the past films and plates were ortho, that's why when you look at landscapes taken in the 1800 and early 1900 the sky is blank, red sensitive, blue blocked like using a dark blue filter on pan films. Orth film rendered foliage well, as well along with pale skin tones, there was an othro Trix for black and white portraits. Orth film is very fine gain so for those who are looking to make large prints it can be useful. Others want to use for very high contrast prints. I'm not sure about Inkpress, I just ordered film which included a roll of Foma Ortho 400 for an experiment. Here in the low desert many clear days, want to experiemnt with landscapes. If orth film is as fine gain as is reported with 1/2 frame maybe possible up to 11X14.

The Inkpress film is a lith film, as is the Arista film. In addition to the printing industry, they were also used in darkrooms to make masks for special printing techniques, such as inserting part of one image into another.

These films vary quite a bit. They can have different speed, different contrast and different Dmax, or respond to different developers. In the print industry they were often used with lith developers that promoted infectious development, producing two tones: dead black and clear film. They're designed for rapid processing (e.g., 30 seconds development time with developer at 30C), and have a very thin base that lets you contact print with either side up. You can often also expose it through the back.

I don't know why other people use it, but it can be used in camera as a very cheap large format option, in which context it might the the only affordable option for ULF It can be used to enlarge smaller format negatives for contact printing. I've done both with the Arista film, and it worked well in both cases. One other nice thing is that it will show some sky detail in landscapes.

Find a University art museum and ask for a curator that works with prints and works on paper to find out where the term lithography started out.
Litho film is/was part of an analog process of printing from "plates" thin sheets of metal.
All started with stone (lith) slabs. This (original) process is still going strong.

Matt explained very well the reason why ortho lith films existed in the first place. I have only seen being used in darkrooms to produce internegatives from roll film to do contact printing (Pt/Pd, Van Dyke, carbon, bichromate gum, etc.). Ortho lith films were produced in many different sizes as big as 60x120" and theirs characteristics (contrast, grain, speed) were right for the purpose. The modern lithographic processes for printing plates use laser exposure from a digital file, similar to how RA-4 printers work, and film is not needed anymore. Also most internegatives for contact printing are produced by inkjet, even this has never been an important use of ortho lith film.

Nevertheless, they are attractive for LF or ULF photographers if contrast is tamed (like X-Ray film). Ortho lith film has a very fine grain, it can be developed by inspection in trays under red light, and it could be cheaper than regular BW film (not the case of current Rollei Ortho 25 Plus).

If you'd like to see how lith film was used in darkroom work in the analog era, a search of the internet archive for "creative photo techniques" should turn up quite a few titles that cover the subject. E.g.:

"I don't mean historically. I know that in the past they were used for copying, like in newspapers, or to copy documents. I wonder what market exists today. I use them to make large negatives for cyanotype, but I don't imagine that's a large enough market to merit the product's existence".

As explained by dcy's quote above, I too am puzzled by why the market is large enough to merit the product's existence today Unless I have misunderstood all of the replies their current use seems largely confined to LF negatives and enlarged internegs for alternative processes but even here as at least one reply mentioned inkjet negs seems to be the more common way

Thanks

pentaxuser

pentaxuser said:

I too am puzzled by why the market is large enough to merit the product's existence today

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I think it's mostly leftovers. I don't know if anyone still manufactures it.

The graphic design industry used to use a lot of that film. They very quickly shifted to using none of it. Newspapers used to use miles of it. Hundreds of such newspapers closed up over a short period of time (and I wonder what kind of a dent that put in Kodak's and Agfa's profit). I assume the printing industry now directly exposes its plates using a laser (or something). There are certainly no developing technologies that use that film.

Okay, so I did some digging and I found out that agfa still manufactures several photolithography films for use in PCB manufacturing. Given the "made in Belgium" label on arista Ortho lith packaging, I suspect that might be who they're sourcing from.

thinkbrown said:

Okay, so I did some digging and I found out that agfa still manufactures several photolithography films for use in PCB manufacturing. Given the "made in Belgium" label on arista Ortho lith packaging, I suspect that might be who they're sourcing from.

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Eastman Kodak is active in making flexible circuit boards, which probably shares some technological roots with the old lithographic products.
The black and white archiving films may also be orthographic.

Ortho films are also used in document copying, as you don't want the red sensitivity. Many archives use film as a more permanent medium than digital to copy fragile documents.

thinkbrown said:

Okay, so I did some digging and I found out that agfa still manufactures several photolithography films for use in PCB manufacturing

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Are you sure? I think Agfa has divested pretty much all of its film manufacturing to other parties. For instance, the imagesetter film manufacture is in the hands of a Chinese company if memory serves. To the best of my knowledge, Agfa doesn't manufacture film anymore.

I'm also not sure whether any silver halide film is used in contemporary PCB manufacturing. It's photopolymer coated directly onto the copper-clad board and then probably laser exposed, or solid state UV through an LCD.

thinkbrown said:

Given the "made in Belgium" label on arista Ortho lith packaging, I suspect that might be who they're sourcing from.

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This suggests it's old stock, or manufactured by whatever company that has taken over this business from Agfa.

MattKing said:

Eastman Kodak is active in making flexible circuit boards

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But I think in that case it's not so much an imaging aspect of those 'boards'. It's the material itself AFAIK.

Craig said:

Ortho films are also used in document copying

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'Are', or 'were'? How much document copying on film is really happening today? Not a whole lot I bet. I can't think of any use case where this would have any real, objective and sensible benefits over a chemical workflow.

Much of what's said about applications in the present tense in this thread seems to date to pre-2000. Things have changed.

I use Ortho Loth film to create masks for BW printing. My current workflow has contrast reduction masks and unsharp masks (they are fairly similar, different in densities)

The rest of your question is answered above I believe…

koraks said:

Are you sure? I think Agfa has divested pretty much all of its film manufacturing to other parties. For instance, the imagesetter film manufacture is in the hands of a Chinese company if memory serves. To the best of my knowledge, Agfa doesn't manufacture film anymore.

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All I know is they list a number of products on their website under the "Idealine" product range: https://www.agfa.com/specialty-products/solutions/industrial-imaging/idealine/

I don't have any insider knowledge on this, but presumably it's still available for order if it's listed

It certainly looks that way. For how long, that's the question.

koraks said:

It certainly looks that way. For how long, that's the question.

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Presumably it's a cheaper option in mass production. I'm not super well versed in the industry but it sounds like maskless options are more flexible for prototyping, whereas masks are still used in mass production for greater speed.

It sounds that most semiconductors are still made with a masked process too, though what that mask is made of I haven't been able to determine. ASML doesn't seem to list many details online

I find all the replies rather middling by their misunderstand of the terms.

Litho/Lith films are ultra-high contrast films designed to be used with Lith developers which are infectious developers that greatly enhance edge sharpness. Their primary use was in making Litho printing plates.

Line films are high contrast, designed for high contrast or lith developers, but can also be processed for masking in lower contrast developers..

Ortho, is a different kettle of fish, Lith & Line films are Ortho so high blue sensitivity, but then also meant to be used with Tungsten lighting, which has less Blue sensitivity. Then there continuous tome Otho films like Ilford Ortho Plus, essentially loke FP4 Plus but ortho.

I've used huge quantities of Ilford Ortho, various Lith & Line films, usually for stripping negatives together or for adding text.

Ian

No silver halide film as we know it is used in regular semiconductor manufacture. Those semicon.lithography masks are called reticles and they are generally made using e-beam (electron beam) technology. The base material is essentially glass, rather thick, and the images are reduced by a factor of 4, so the reticle is 4x larger than the projected image. There's a fundamental difference between regular reticles, which transmit UV light, and the more modern EUV masks, which by necessity are reflective. The former are the bulk of the market though, since EUV is only used for critical layers on high-end devices (high-end logic and especially memory). It's possible that the transmissive masks use silver to create density; is have to look that up. I vaguely recall this, but I never looked into reticle production very deeply.

While there are conceptual similarities, PCB manufacturing is a different field from semiconductors. The industrial networks are also distinct.

I have a roll of Foma Orth 400 on the way, the data sheet reports 85LPM with a moderate contrast curve. I would have thought better than 85LPM for resolution. What developer? I have D76, Clayton F76+ and MCM 100 on hand. In the past I have developed orth 4X5 in Dektol under a red sidelight, but 35mm much too small to see emerging details.

I recently found an old package of Arista 8x10 lith film for a good price. Tried 8x10 camera negatives, didn’t like it enough to continue the experiment. I will probably try to use it for making 8x10 enlarged transparencies from 35mm negatives. That could be more fun.

In the 1990s I found a huge box of lith film in the school darkroom and messed around with it for kicks. I discovered I could make cool photograms of leaves and whatnot, then partially develop in regular print developer and immediately drop it in the stop bath. The result was an “artistic” swirly patterned negative that was kind of fun. I also made a few PCB masks for the electronics class using a horizontal copy camera. I had no experience, but I knew where the power switch was, so that was good enough to be the expert.

There is a distinct reason for the popularity of Arista Ortho Litho film. It's really cheap, and comes in quite a range of sizes, including some big sizes. It also has a slight texture which minimizes Newton rings in contact printing. Various kinds of Alt printmakers have innovated numerous uses for it. On the downside, high contrast films like this are hard to develop evenly with low contrast continuous tone developers. Some tricks are involved. This film is also very thin, making it sag problematic if used in sheet film holders.

The Arista version is about 75% blue sensitive, and 25% green sensitive. I sometimes use it to make b&w internegs from color negatives which typically need a contrast boost for this kind of application. It's a double negative method. The first neg is for sake of a med contrast interpositive, and necessarily made on a pan film like TMax. Then that in turn is contacted onto Ortho Litho for sake of the final higher contrast printing internegative.

One of the main uses for Otho litho film in the past was for highlight masks, both pre-press and in relation to color darkroom processes like dye transfer and Cibachrome.

koraks said:

No silver halide film as we know it is used in regular semiconductor manufacture.

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My point wasn't that lith film was being used for semiconductors, just that maskless options still don't appear to be the default. Maybe some large feature old "jelly bean" components still use silver masks, but I haven't found any info on that. Wouldn't shock me if some company is still producing 555 timers off a mask from the 70s haha. For every bleeding edge ryzen 9 whatever, there's an awful lot of cheap old designs being made

thinkbrown said:

Wouldn't shock me if some company is still producing 555 timers off a mask from the 70s haha.

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Yeah...but no. That'd be too expensive. You can cram a lot more of those onto a wafer today, so even if masks from that era would have been around, they'd be too expensive to use (not to mention yield would be also abysmal due to high defect rate).

Thank you all for all the information. This is really fascinating.