Does RC paper give deeper blacks?

Hello everyone,

 

There’s one thing that’s been puzzling me in the darkroom: I much prefer FB paper, but many B&W images actually turn out better on RC paper, because in my limited experience RC paper gives richer blacks. Everything else (filter, paper grade) being equal, a negative printed out on FB paper will often look flat and muddy, whereas the same negative printed on RC paper will give much better contrast.

 

What might be the possible cause? I’ve been using Adox MMC paper for several years, which seems to be manufactured according to an old Agfa recipe. As vintage Agfa prints often look wonderful, I assume there’s nothing wrong with the paper and that it’s just a matter of my questionable darkroom technique. Or is FB paper just generally more difficult to handle, and RC paper more tolerant of faulty (under-)exposure? Or are there other FB papers that give results closer to RC paper?

 

An easy solution of course would be to stop using FB paper, but apart from the deeper blacks I dislike RC paper, it looks and feels too plasticky for my taste. I use old cameras (mainly a Rolleiflex TLR built in the 1950s) and I’ve noticed that vintage prints are often less contrasty than contemporary images, but of course the masters of old knew how to print decent blacks.

 

Any hints appreciated,

 

Carsten

It's the glossier finish that gives deeper blacks.

 

If you print on glossy fibre paper and then 'ferrotype' (hot-glaze) the print, the blacks will be even deeper.... as long as you don't get a strong surface reflection.

 

Another issue is that there are less silver salts in most modern papers, and modern paper developer recipes seem weaker to me. They're probably geared to developer-incorporated RC papers.

 

You can't beat D-163 IMHO.

Are you using the same developer and developing time for both? In my experience FB paper benefits from a longer developing time than RC papers, and as Rodeo Joe says, print developers formulated for RC papers that are developer incorporated might be a bit wimpy for FB papers.

It's all in the surface finish and IMO, ferrotyping fiber prints sucks for the amateur. The big photofinishers used to do very well with continuous driers but my success rate with a squeegee and flat plates was miserable. Various treatments were touted as the answer, but the process still sucked. That said, when I did succeed, the blacks were fantastic. Naturally, don't under develop. I haven't printed in some years but I always thought RC papers didn't do quite as well as properly done fiber.

A high gloss finish add about 1 contrast grade, maybe more. You will never need to experience the problems we had, in the early days, to achieve such a finish.

 

All the photo labs that wanted glossy prints used a method called the ferrotype process. We used sheet metal plates, polished to a high gloss and then enameled, or chrome plated, or stainless steel. The well washed print was then squeegeed onto the plate using a rubber roller. In the photofinishing plant we had heated print dryers with giant chrome plated drums. We needed to keep the polish on these surfaces so we spent a lot of time cleaning and polishing.

 

The print, once squeegeed on the plate could be air-dried or forced dried with heat. The problem was separating the print paper from the ferrotype plate. If not immaculately clean, the print would not self-separate. The only way to remove it was water and peel off, usually this destroyed the print. On the market were several pre-soak concoctions both for black & white and color prints. The winner was Pako of Minneapolis (PakoSol / PakoChrome).

 

O’ the joy of RC paper (resin coated). The glossy version of this paper naturally air-dried to a high gloss, no ferrotyping needed.

Right, I have ruined lots of prints trying to separate the sheets from the metal plates. I hated this process. But the final print, if sucess, was great. I think I sometimes used some kind of high glossy finishing product to avoid problems.

Not so long ago, I tried to replicate the same process with MG FB paper... the paper doesn`t got stuck to the metal plate, but there was no change on the glossy surface. And the paper was not even flattened, so it doesn't work anymore.

Thanks to everyone for your suggestions! I tried ferrotyping once many years ago, but failed miserably. But as I wasn't aware that ferrotyping improves the blacks I'll try again. For FB paper I use longer development times than with RC paper, but still the results are often unsatisfactory. The blacks do become (a bit) deeper, but sadly the main effect of prolonged development seems to be to turn the whites into a mushy grey. The more underexposed the negative, the more pronounced this effect :-) Well, maybe I should attend a darkroom class.

Whites should still hold with longer development, depending on exposure of course. I lived in a Kodak world, so with Dektol I routinely developed 2 minutes at 1:2 dilution. Paper doesn't age like it used to, so any paper more than a year or so old is suspect. You should also do the fogged-paper safelight penny test. The pre-fog is important for sensitivity. With underexposed negs (made a lot of those myself) you usually need to increase the contrast to hold the whites, sometimes more than the available paper grades or filters will allow. You need a book. It was expensive, but now it's free! Be sure to download Ctein- Ctein Online-- Post Exposure Sample Edited November 26, 2020 by conrad_hoffman

but sadly the main effect of prolonged development seems to be to turn the whites into a mushy grey.

Then either your safelight isn't truly safe, or your developer isn't 'strong' enough.

 

There used to be restrainer products sold as 'developer improvers'. Not sure if they're still available, but if so they might help.

 

Or you could try another type of print developer. Definitely give a D-163 clone a try.

Why glossy paper is more contrasty:

 

We view film, both negative and positive, by transmitted light. In other words we look at our negatives and slides by holding them up to a light or projecting them via light that traverses the material. The average difference, clear film to max density is about 1:1024. Since each f-stop is a 2x delta from the next, we are talking about a 10 f-stop dynamic range.

 

We view prints on paper by reflected light. A nearby lamp plays light on the print we are viewing. This print’s surface reflects away some of this light. The remainder will transverse the print’s emulsion. As it travels, it encounters clumps of opaque metallic silver or, in the case of a color print, it encounters colored dye. In both cases, a reduced amount of light arrives at a white reflective coat, a primer that holds the gelatin emulsion to the paper.

 

This primer layer has a name, it is “Baryta”. For years and years this nearly pure white coat is a suspension of barium sulfate. This stuff is now man made, originally a clay found in nature. Today it is laced with special dyes that have fluorescent brightening properties.

 

When the light that is illuminating the print arrives at the Baryta, it has been modified considerably by obstructions suspended in the print’s emulsion. Now the enduring light rays reflect back into the print emulsion which they must traverse again. In other words, the image you are eyeing is formed by light that makes two transits. This fact allows the pint emulsion to be quite weak as compared to film emulsions, In other words print paper emulsion a made with far less silver and or dye than a film material, about the ½ the silver or dye on paper based emulsion.

 

Now that the print viewing light has exited the print paper, this forms the image you see. If the print paper has super low gloss, you will see a contrast range of 1:32, that’s 5 f-stops. If the print has a high gloss, the contrast range will be 1:64 or about 6 f-stops.

 

That’s the rest of the story – glossy paper is more contrasty!