Has anybody got a successful calotype negatave?

[Fulvio]

In the last months I've experimented salt printing and found out how to make decent prints

The process is very easy and for anyone interested I can share my experience. For example, I noticed a slight difference of tone if you fix salt prints in 10% hypo solution or use instead a weak fixer for standard silver prints; the latter is more pinkish-purplish while classic hypo delivers a more brownish image (the difference is subtle).

Salt prints have definitively a nice vintage-look. The highlights of my prints are never white, but I have some tone in the whites and this makes them more old-look like.

In my efforts to make prints appear "antique", the next step was obviously to learn how to produce calotype negatives.

While saltprint process is quite easy and straightforward almost like cyanotype printing, I met some difficulties with calotype negatives.

In low tungsten light conditions, I first coat a sheet of paper with a solution of 11% silver nitrate (the same I use for salt prints), let dry and then immerse the paper in a solution of 5,6% potassium iodide. The paper turns primrose yellow, especially on the silver coated side. I leave the paper in the potassium iodide bath for 2-3 minutes, then I rinse it for about 1 hour and half. The paper is then hanged to dry. At this stage, the paper remains clear even if exposed to light; no stains or brown spots whatsoever, just a uniform faint yellowish tone in the coated side.

The next day, under red safelight conditions, I prepare a solution of the following: to each five drops of a 11% silver nitrate solution I add a drop of 80% acetic acid; to each of these {5+1} drops I add an equal amount of drops (e.g. 6) of a 1% saturated solution of gallic acid. Then add 8 ml of distilled water.

While still in red safelight conditions, using a clean brush I coat the previously iodized paper with such solution. At this point, though, the paper turns dark... Not completely black, but visibly darker. I'm quite perplex, I guess there's something wrong.

In fact, after I finished coating, I put the sensitized paper in a 4x5" sheet holder (the paper was initially cut to fit the size) and expose it using a normal large format camera. I tried exposures ranging from 2' - 5' at f8 in a sunny bright area.

When I bring the sheet holder back to the darkroom and open it is almost gray as it was before, perhaps slightly darker. I try to develop the paper using an equal amount of silver nitrate and gallic acid (plus one drop of acetic acid every 10 drops of silver nitrate). The paper turns really dark, totally black. I wait for 1-2 minutes and the situation doesn't change. By fixing the paper in a standard hypo solution, the paper just stay black. I can tell the "black" has the same tone of calotype negatives I've seen around the internet, but still is black and I can't see anything on it.

What do you think went wrong? Should I try another kind of paper? The one I used is a schoelleshammer and should be a rag paper... It seems to take the iodizing stage quite well. It's the silver gallo-nitrate sensitizing part that produces an odd result. The paper should remain clear while sensitized and become dark only during a quite long exposure to sunny light....

The silver nitrate and the potassium iodide alone don't seem to react badly to the paper, otherwise I would have brown stains and spots. Could it be something wrong between gallic acid and silver nitrate?

Does anybody have some experience with calotype negatives?
I could switch immediately to another kind of paper, before doing so I wanted to ask some help... The schoelleshammer 6 paper is the smoothest and lightest paper I have here; I got some zerkall, fabriano 5 and arches acquarelle and platine, but they're all relatively heavier and rough.

thanks

 

[Fulvio]

ok... so far while I was experimenting different dilutions of the sensitizer, I found the following:

regardeless their proportions, combining acetic acid (80%), silver nitrate (11%) and gallic acid (1%) in distilled water does not produce visible changes in the color of the solution, which remains transparent (in safelight conditions); but if I bring this solution in contact with the previously iodized sheet of paper, this turns immediatly black.

This solution turns black only when I put it in contact to the iodized paper. So, I tried to put each element of the sensitizer on the paper separately.

First I've dropped a single drop of silver nitrate directly on the iodized paper: nothing happened; but when I added to this a drop of gallic acid... whooom... I got an instant black spot on the area even under red light. The same happens if I invert the order and put one drop gallic acid first and then a silver nitrate one.

By mixing silver nitrate and acetic acid (in a<b proportions) before adding the drop of gallic acid, the blackening is less effective, but still makes the paper useless for camera exposure. So, I tried altering concentrations of the chemicals, but so far I haven't got a working combination of the three.

According to my sources, the paper color should not change after the iodizing part, which turns its color slightly yellowish. But as far as I can see there's a reaction between silver nitrate and gallic acid when both enter in contact with the iodized paper that produces an instant coloration of the paper itself without any exposure to considerable light.

What do you think?

F.

 

[htmlguru4242]

Perhaps the paper was exposed to light after the silver iodide coating?

 

[Fulvio]

Perhaps the paper was exposed to light after the silver iodide coating?

mmm... but the iodized paper isn't light sensitive, is it?

I mean, some sources even mention the possibility to expose the iodized paper to sunlight prior to sensitizing for a couple of hours to improve final contrast...

I don't do that.

All I do is to coat the paper with 11% silver nitrate first. After drying with an hairdryer, I leave it in a bath of potassium iodide for 2-3 minutes. These operations are made under a 40w tungsten light bulb, the same I use for saltprints and vandykes without any visible fogging. After iodizing stage is complete, I wash the paper for at least 1 hour, under the same light (or no light at all if I leave the room). The paper is finally hanged.

Initially I made some mistake and brushed the potassium iodide on the paper directly, instead immersing it in a bath of the same solution. I've soon realized that the potassium iodide must be a lot more than silver nitrate to convert the latter. It has to go also on the back of the paper. Without using a full bath, the paper will show typical silver nitrate brownish spots when placed in the washing bath (I guess as a reaction to organic matter present in tap water and light - organic matter is what makes silver nitrate light sensitive as far as I know).

When I started immersing completely the silver nitrate coated sheets into a solution of 5.6% potassium iodide, all brown spots disappeared. I still got some iodized papers here that haven't been sensitized yet. I iodized those 3-4 days ago and they show no spots or stains: just an uniform white-yellowish color which should be normal at this stage.

Problems seem to start appearing now at the sensitizing stage.

Anyway I could make some test and doing all the operations under red safelight if you think so.

Have you ever produced some good calotype so far?

thank you very much

 

[htmlguru4242]

I do not have experience with Calotype, but based on your procedure, i think that that could be the issue; I could be completely wrong, but the way I see it ...

Silver nitrate + Potassium Iodode yeilds silver iodide, which is light sensitive; it is not extremely sensitive, and it does not print out like silver chloride does, though it is light sensitive. Over an hour in tungsten light, it becomes exposed from the light that is present.

Gallic acid and silver nitrate functions as a photographic developer. Therefore, when it is coated with this solution, it develops out the exposure.

Try coating the iodized paper under safelight.

That's just my suggestion based on reading and (perhaps flawed) logic.

 

[Photo Engineer]

Silver iodide is quite light sensitive. Sensitivity extends far into the visible region of the spectrum. In fact, pure silver iodide is almost ortho sensitive all by itself with no sensitizing dye.

It cannot be developed by conventional developers, and that is why calotype uses the process it does. Silver iodide made this way also produces very fine crystals and that is why the speed is rather slow.

PE

 

[htmlguru4242]

That's interesting, PE

How is silver iodide developed, then?

 

[Fulvio]

ok, I'm convinced, I'll do all the iodizing part in red safelight, including washing of the print. Tomorrow we will see if that was the problem.


thanks

 

[Fulvio]

Try coating the iodized paper under safelight.

I do sensitize my already-iodized papers with gallic acid + silver nitrate under safelight, as prescribed in my books. What I do in standard tungsten light is the previous iodizing part (silver nitrate coat, then potassium iodide bath). Tonight I'll try doing that under red light as well, including washing.

thanks, I will post details if it works

 

[Photo Engineer]

Development of silver iodide is done as described above for calotypes.

It can also be done with very high strength alkaline developers, but I have not seen this done for over 30 years. I know it can be done, but it is very very difficult in most cases and I'm sorry that I have no specific developers to suggest.

PE

 

[Fulvio]

damn!

yesterday night I've iodized a few more 4x5" calotype sheets to fit my graflex... This time under a red safelight, the same I use for bromide papers and liquid light emulsions and which never gave me fogging problems with those. The washing part has been carried in total darkness as I left the room for an hour and half, leaving the papers in running tap water.

Well, today I exposed a couple of such calotypes, but during sensitizing (still in safelight), they turned again black as the sensitizer touched the sheets!

I tried to expose a dark sheet anyway but result didn't change. I also tried to expose a iodized but non sensitized paper but it turned black anyway after exposure during development (similar gallic acid + silver nitrate + acetic acid solution used for sensitizing).

There's something bad that happens when the gallo-nitrate solution meets the silver iodide paper. I've left also a iodized paper in complete light for half day, masking half of it with a book. There was no change in the paper, no signs of exposure nor differences of tone: just an uniform white-yellowish color.

Although is always a good idea to work in dimmed light or safelight conditions, maybe I should assume that the papers were not fogged during iodizing or afterwards... Talbot and pioneer calotypists used to work in candle light or dimmed light and this kind of tecnique should print veeery slow and shouldn't take light from a 4w safelight! (I use a led safelight, its wavelength falls in the red spectrum and is very realiable with modern fast papers).

Could it the post-iodizing wash bat insufficient? My sources state 1-2hrs, one source generically suggest "several hours". I noticed that badly washed iodized calotypes turn brownish and the papers I got here were clear.

I'll try to ask for help in some chemistry group on usenet or somewhere else... I'm surprised though there are not many calotypists around... Even on alternativephotography.com there's no recipe for a calotype negative and calotype negatives are listed as a "forgotten process"!

 

[Fulvio]

new day, new experiment, same result

Since the papers iodized in red light turned black anyway, I started figuring that it could have been due to an excess of silver nitrate. So I made a new batch (again in the safelight) of iodized papers, this time using a merely 1% silver nitrate solution. Today I was about to expose them, but they still turn black when the solution of silver nitrate gallic acid and acetic acid comes into contact with the iodized paper. For another sheet I also tried to reduce the amount of silver nitrate in the sensitizer, but that didn't set a difference. I've finally exposed a paper without sensitizing it before, but then when you have to develop it in a similar solution of the three chemicals mentioned, it turns irreparably black again.

I tried to contact Richard Morris, a guy who wrote an article in "Coming into focus" (book edited by John Barnier) which has been a good source for me for many old photographic tecniques. I hope he will reply and help me sort out what is wrong.

 

[htmlguru4242]

This is, once again, a stab at randomness, but have you tried putting a drop of the sensitizer on non-iodized paper? Perhaps its an interaction with the paper ...

 

[Fulvio]

This is, once again, a stab at randomness, but have you tried putting a drop of the sensitizer on non-iodized paper? Perhaps its an interaction with the paper ...

yep I did that on 2-3 different papers I used: the sensitizer remains transparent and the paper clear. The sensitizer itself tends to become darker (although not really deep black) if left in the light & air for very long (for ex. I accidentaly left a small plastic glass with some sensitizer in the darkroom for 3-4 days and it turned dark).

I've found a XIX century text covering calotype making among other processes:

http://stason.org/TULARC/recreation...ctice/11-Chap-IX-Calotype-And-Chrysotype.html

There are some alternatives proposed by Talbot himself, like iodizing, the brushing with gallic acid first and later with silver nitrate, I tried that too without any success.

One thing it is left to try would be to have the iodized paper washed in distilled water instead tap water: perhaps organic compounds and carbonates found into tap water react with silver...

 

[TheFlyingCamera]

could it be the paper you're using?

For another take on how to do Calotypes, try:

http://www.amazon.com/Primitive-Pho...f=sr_1_24/103-6486750-5230265?ie=UTF8&s=books

If I remember my reading from this book, one of the things he does is to wax the paper (this may be AFTER making the negative, but I don't recall).

Here is a quote from the chapter description on Amazon-

Chapter 4, "Calotype Paper Negatives", is dedicated to 2 types of paper negatives: wet-paper process and waxed-paper process. Wet-paper is considered most appropriate for portraiture because the negatives must be used quickly after sensitizing, before they dry out. Waxed-paper requires longer exposures but is dry and need not be used quickly. These negatives are suited to landscape, architecture, and anything that requires time to locate. There are lists of recommended papers for both processes. Step-by-step instructions take the reader through Iodizing, Sensitizing, Exposing, Developing, and Waxing the negatives. You can choose from several recipes for Iodizing and Sensitizing solutions.

 

[Fulvio]

could it be the paper you're using?

If I remember my reading from this book, one of the things he does is to wax the paper (this may be AFTER making the negative, but I don't recall).

waxing is generally raccomanded after the negative is printed and developed; waxing allows a better transparency, resulting in a paper negative easier to print... Also oiling is suggested as an alternative to waxing. It makes sense...

I've found another source for calotypes...

here: http://www.arp-geh.org/indexsep.aspx?nodeidp=241

they're based on the notes of a certain Greenlaw who described some variation of the process in 1869. Tonight I will try some of these alternatives and let you know.

(by the way, the link above directs to a very interesting website, with a lot of both technical and historical informations on early photographic processes)

 

[Fulvio]

I tried the methods described in that PDF document, but I still have the same problems: whenever the gallic acid mixed to silver enters in contact with silver iodide on the paper, this turns black, even if unexposed.

I thought this was due an insufficient washing or organic contamination of the iodized paper while in the washing bath. So I gave a try to the washed precipitate method. It is quite easy. With such method, I mixed silver nitrate (11.4%) and Potassium Iodide (5.6%) in equal parts. A precipitate forms and sits on the bottom of the solution. Then I started decanting all the liquid, leaving only the precipitate. I added distilled water and repeated the operation, washing the precipitate with several changes of water. Then finally I added a certain amount of potassium iodide until the precipitate redissolved becoming a very milky solution. I've spread this solution onto the paper; the paper became yellowish. When dried, I applied a solution of 11.4% silver nitrate without drying the sheet (operation carried under safelight). By doing so and exposing the negative immediately, an image forms on the paper. I tried this overnight so I pointed the camera (a 4x5" Graflex) toward a lamp. After 20' exposure at f8, I developed the paper with usual solution of gallic acid + silver nitrate. I could finally see the shape of the lamp's light bulb (very dark) surrounded by a very dirty gray area. I had to stop immediately, otherwise all the image would have turned black. So I tossed the negative into fixer and the image fixed. Now I have this big gray spot with a dark light bulb image negative

But although I can call this somewhat satisfactory in a sense, it's a very odd result.

Calotypes should be supposed to develop in a very long time. All the sources mention developing times of ten to sixty!!! minutes. When I pour a diluted solution of gallic acid and silver nitrate over a iodized sheet of paper, this turns black in a few seconds.

Today I made new experiments, but this time I was unable to deliver anything like yesterday.

For example, I made another experiment by immersing the paper straight in the 5.6% potassium iodide solution. The paper doesn't turn in any color. After it is dried, I start coating it with a 11.4% silver nitrate solution. The paper turns yellow (I do this in safelight, but I've realized later what color the paper is then). After paper is coated, while the sheet is still damp, I start exposure. An image forms on the paper and you can clearly see it after you open the film holder of the camera. But then, when you try to develop it with gallic acid & silver nitrate, it turns completely black.

I tried not to develop a sheet iodized with this method ("no pre silver bath") in a gallic acid developer. Instead, I tried standard b+w developers and also plain water, like I do for van dykes and salt prints. But the image won't develop or just turn slightly darker (probably due to the contact of silver nitrate with organic compounds in water - it doesn't turn black as with gallic acid, though).

I want to try now the Greenslaw process, which is another no-pre-silver method, but involves use of elemental iodine as an additive to the iodizing bath. The authors of that PDF have been successful with that method. Actually it looks like that all of my sources have been successful with their own method, but nobody mention this problem with gallic acid and I still have to understand what's wrong with mine. I'd wish to be a chemist in such moments...

Now if you excuse me, I'm going to bang my head on the wall

 

[htmlguru4242]

Perhaps you are overexposing?

Everything I've read metnions there being no image on the page after being removed from the camera ...

 

[Jerevan]

Note: I am not making calotypes (yet) but have you read Richard Morris' article in Coming into Focus? I suppose you know what a buckle brush is, but in case not, it's basically a small plastic or glass pipe with a wad of clean cotton in one end. It is necessary to use this tool, as this process seems to be very dependent on cleanliness and not getting things contaminated. Hope it helps in some way.

First part:

1. using a buckle brush, sensitize the paper with 7.5% silver nitrate solution.

2. Immerse the paper totally in 5.6% potassium iodide solution for at least 2-3 minutes. It will turn primrose yellow.

3. Wash paper for several hours to remove the potassium nitrate. Hang to dry.

Second part:

Solution A: Add 11.4 grams of silver nitrate into 75 cc distilled water, mix thoroughly and finally add distilled water to make 100 cc.

Solution B: Into 28.4 cc solution of A, 5.5 cc glacial acetic acid.

Solution C: Into 100 cc of distilled water, add gallic acid and mix thoroughly until no more will go into the solution. This is a saturated solution of gallic acid.

Solution D: (working solution) Add three drops of B and three drops of C into 4 cc of distilled water. This will cover a full plate (6.5 by 8.5 inches). Mix this fresh every time you sensitize an iodized paper.

1. With a fresh buckle brush, coat the paper with working solution D onto paper.

2. Blot the paper carefully with a clean blotting paper evenly all over. Let dry in the dark. The paper should be slightly moist when it goes into the camera.

3. Cut paper to size and put in holder. This can be done under red safelight.

Third part:

1. Using the solutions B and C mixed together in equal quantities, 5 cc each for a full plate negative, brush this over the calotype negative. The article says the image should "appear almost immediately".

2. Use another separate, clean buckle brush. Apply an unspecified amount of solution C. Don't get the paper too wet. Allow the image to develop until it stops increasing in density, then recoat again with solution C. The density can be checked, as this can be done under red safelight conditions.

3. Wash briefly in tap water, then fix in plain hypo solution for five minutes until yellow potassium stain is gone. If five minutes isn't enough to remove stain, continue to wash.

4. Wash thoroughly for 10 minutes in HCA or else at least for one hour.

5. Dry face up on fiberglass screen.

There could be faults in this, but I've checked it in some detail. If unsure about the steps in the process, look in Coming into Focus by John Barnier, ISBN 0-8118-1894-2.

 

[Fulvio]

Perhaps you are overexposing?

Everything I've read metnions there being no image on the page after being removed from the camera ...

The only partially successful calotype (if can be so defined) of the "light bulb" I have, required an exposure of several minutes. And in the picture there's only the shape of the light bulb, but not that of the lamp.

Even with the no-pre-silver method, when I can directly see somthing on the negative before development, I'd say that the speed is more or less the same of a salt print - which is rather slow (mine print in 5-8 minutes under strong UV lights).

Anyway I also thought about the possibility of having a very fast calotype in my hands. So I tried exposures as short as 1 minute f11.

The problem is when I try to develop anything: it turns black.

It can't be a problem of contamination as I use only distilled water and, yes, I'm using the buckle brush whenever possible.

 

[Fulvio]

Note: I am not making calotypes (yet) but have you read Richard Morris' article in Coming into Focus? I suppose you know what a buckle brush is, but in case not, it's basically a small plastic or glass pipe with a wad of clean cotton in one end. It is necessary to use this tool, as this process seems to be very dependent on cleanliness and not getting things contaminated. Hope it helps in some way.

thank you very much... I'm so sorry that you had to copy all that text from the Coming into focus chapter on Calotypes. I have the book right here and in fact I wrote to Morris (I found his email address on the internet).

My main ources for alternative photography are Coming into focus edited by John Barnier and The book of alternative photographic processes by Christopher James. I do often add readings from the internet to expand my knowledge about a single process, like the Greenlaw PDF notes I linked in a previous post in this thread.

I started using a "buckle brush" for Calotypes and I find the idea quite effective for such process. It's only downside is that loads too much chemistry compared to a regular brush.

 

[Jerevan]

Ah well, Fulvio, I figured that out, when re-reading the thread again!

For future reference, I'll leave my write-up exercise in the earlier post. But from what I read of the experiments you are doing, it seemed that you don't use the recipe in the article?

If I were you, I'd stick to one recipe (whichever you choose), use the same techniques you've used and just change the paper type at first.

 

[Fulvio]

I still haven't got a negative...

the problem remains development of the negative:

whenever the developer (gallic acid with a very small quantity of silver nitrate and acetic acid) meets the silver iodide paper, this turns black, regardless if exposure occurred.

I don't know if this is due preparation of the iodized paper. To reduce this possibility, I've tried several methods to obtain a iodized paper. Most manuals, including the Morris article in Coming into focus, only describe one.

A) Talbot method: first coat paper with silver nitrate, dry, then immerse in potassium iodide solution. Paper needs to be washed to remove excess potassium nitrate; sources indicate "several hours" of washing, but probably 1 or 2 are more than necessary; permanence of the paper into the bath of potassium iodide is uncertain, some sources mention 2-3 minutes while others 20 to 60 minutes. After iodized and dry, the paper is coated with a sensitizer. But then, at this step and even before exposure, my papers have always turned black. I never came any further with this method, that is probably the most cited in modern books, which do not mention the following ways of making a iodized paper.

B) No-pre-silver method: instead of coating the paper with silver nitrate first, one can directly immerse the paper in a solution of potassium iodide. Additives such as potassium bromide or elemental iodide may be used (I haven't yet understood what for). Since paper does not contain any silver at this stage, it doesn't require washing. After iodizing step is complete, the paper is hang to dry and then coated with silver nitrate. Immediately after coating, it has to be socked in clean water for 2-3 minutes. A precipitate forms and the paper is washed. Now you have a washed sensitized paper. My papers didn't turn black at this stage like they were with the Talbot method. But I had the only partial success here, being able only to photograph a neon light bulb (two times, with 10' and 20' exposure). I wasn't able to expose anything else (at the end of this post I'll explain why).

C) Washed precipitate method: whatever method is chosen, the point of iodizing a paper is to create a paper containing silver iodide, especially in its surface. One can form such chemical directly on the paper, like in the previous methods. But one can also prepare the chemical away and later spread it onto the paper. Just mix two solutions of silver nitrate and potassium iodide in equal amounts. A precipitate forms and sits on the bottom of the solution. The top of this solution (its liquid part) contains nitrates and potassium which have to be removed and replaced by fresh distilled water. You can do this by decanting the solution several times. It is very easy to do. After the precipitate is cleaned, potassium iodide is added until it redissolves in a very milky solution. This solution is spread onto the paper, which becomes yellowish. After it is dry, it is finally sensitized with silver nitrate. No washing bath is required as there should be no impurities in the substrate. This method produces same odd results as Talbot method and I wasn't able to deliver a successful print. If it worked, it would be quite practical and fast, as intermediate washing stages of the paper aren't required. As no-pre-silver method, it allows the paper to be exposed dry rather than slightly wet.


By experimenting all these methods and trashing a few dozen of calotypes, so far I understood that there's something wrong when silver iodide, gallic acid and silver nitrate are combined together in this process. With Talbot method I've been unsuccessful because it adopts a sensitizer made of such components. It acts like a developer and in fact turns my images black. With the other two methods, one can sensitize the paper with silver only, hence it doesn't turn black in the sensitizing stage. It will do in the developer stage, where gallic acid is always prescribed.

The books and other sources suggest a developer made with a saturated solution of gallic acid (a merely 1%) and a lesser amount of silver nitrate and acetic acid in proportion. Even though, I've strongly reduced silver nitrate as suggested by the books: only by doing this I was able to deliver the light bulb photograph. This also allowed me to understand the following: no silver nitrate in the developer won't produce any picture; even a little quantity of silver nitrate will develop a picture, but will also turn the whole thing black, slowly or rapidly, depending on the quantity of silver nitrate. If there are any strong highlights in the image (like in the light bulb image I had), there's a chance that this will develop very fast compared to the rest, thus one can stop the development earlier by tossing the print into fixer. Otherwise it will progressively turn completely black (the speed depends on the quantity of silver nitrate in the developer). In any case, the "development" takes place in a few seconds to a few minutes, which seems too fast if compared to what is described in available sources (usually several minutes up to 1 hr).

Is there any serious alternative to gallic acid developer worth trying? How about Pyrogallic acid?

Jerevan: I always start with my books and then make modifications to improve if necessary. But in my case the process didn't work from the beginning and, yes, I tried different kinds of paper. Fabriano 5, Arches Platine, Schoelleshammer 6G, Zerkall Copperprint paper and a leftover from an unknown brand... I don't know, however, how much the paper can actually influence the outcome of a silver based process. With saltprints I can use either of the papers mentioned before without problems.

 

[argent42]

Making calotype negatives

Hello Fulvio, and others taking part in the discussion:

I have been reading your discussion on making calotypes, and the lack of luck you are having, Fulvio. It is heartening to see that there are a few others trying this difficult and oftentimes exasperating process. After having made successful calotypes for the past 4-5 years, using a number of processes -- wet paper, dry paper, waxed paper; Energiatype; Diamond's precipitated silver process; LeGray's waxed paper; and of course, a variety of Talbotypes -- I have found, along with period practitioners, that Calotypy is not for the faint-hearted, requiring an obsessive attention to cleanliness and to detail, as well as to chemistry.

So far you have been doing everything right to try and get a decent result, but the main problem which has plagued you right from the beginning is your choice of paper. The absolute worst kind of paper to use is anything which is described as "archival, acid-free" because the Calotype processes require that the paper be 100% cotton fibre, and slightly acid. "Acid-free" generally means that the paper has a layer of, or its pulp is mixed with, calcium carbonate. Calcium carbonate will cause the paper itself to react with acids (particularly acetic and gallic) and result in the blackening you are experiencing.

Advice: stay with one formula (Greenlaw's is easy to start with), and use a 100% rag paper with at least a neutral Ph. There are very few papers which fit this need. I have experimented with dozens of papers, including some which I am trying now and which may be promising, and found that very few papers will work. They are: Crane's and Southworth's stationery, and tracing papers by Clearprint and Bienfang. The former two are thicker papers, use more chemistry, but have good wet strength; the latter two are thinner and sharper, but have terrific curling when wet and rather poor wet strength.

Two recent Calotypes of mine will be seen soon (I am told) in one of the galleries in the www.alternativephotography.com website, as well as in their new book coming at Christmas. In addition, I will posting both Calotypes and their accompanying salted and albumen prints at my own website, www.VisionsInSilver.com, by the end of this year.

Keep up the spirits! Of all the processes available for making one's own photographic images, the Calotype has to be the most exacting and difficult. Good Luck!

Christopher A Wright

 

[Fulvio]

Christopher,

thank you so much for the help! I knew there must have been someone around the world who tried this!

Someone in this forum suggested the paper as a possible responsible, but my sources didn't explain what happens using a "wrong" paper. Ok, Morris and others suggest specific papers, but do not mention clearly the reaction I had with gallic acids and calcium carbonate. I thought the choice of paper was just a matter of negative usability for printing a positive.

I called my art supplier and he has got a block of Crob' art paper by Canson. It is a kind of paper listed in that PDF article about Greenlaw experiments, so it should work for Calotypes. Unfortunately Strathmore, Southworth and Crane's papers can't be found easily here... I live in Fabriano land... but at least Canson, Arches and a few others are popular as well. If it's ok, I will stick with the Canson.

Carbonates are detrimental also for Cyanotype process and for iron salts processes in general but I didn't assume it was the same for the silver-based calotypes (silly me I don't know a thing about chemistry). Anyway, for Cyanotypes is often suggested to immerse a sheet of paper in vinegar or a solution or citric or acetic acid to lower paper's ph and to get rid of the carbonate effects. I guess the same doesn't apply for calotypes...

Again, thank you so much for the help. Will try the new thing as soon as possible and let know.

best wishes