A Color Monobath Developer Formula

[koraks]

Can I ask what "styrax" is

Most likely a translation artifact. The different versions of the formula appear to be ballpark starting points that should be 'dialed in' to suit a particular type of film.

 

[pentaxuser]

I'm also curious what styrax is. According to search engines, it's a balsamic resin obtained from the cut trunks of trees of the Styrax genus.
But I can't be sure that Google Translate simply made a mistake in translating, or rather OCR reading, the Chinese characters.

Perhaps OP could dispel our doubts.

Thanks If it is the styrax that you mention then you'd imagine that more might have been said about it in the translation

However if we can assume that the "styrax" is a mistranslation and is irrelevant to the process then the whole thing looks just too good to be true. If the colours are all OK and always OK then as I said in my post I am amazed that one of the big colour film companies never came up with this sort of process

pentaxuser

 

[koraks]

if we can assume that the "styrax" is a mistranslation and is irrelevant to the process then the whole thing looks just too good to be true

If there really is "styrax" in there somewhere, is it then not too good to be true?

 

[Alan Johnson]

ChatGPT:

What is Styrax used in Chinese photographic color film developer?

ChatGPT said:​

In Chinese technical literature on color-film processing, the word Styrax (安息香, benzoin resin) refers to a coupler-solvent / gelatin-swelling auxiliary that is added to color negative developer solutions.

Why it is used​

Color film developers (e.g., C-41 type) must allow the color-forming couplers inside the emulsion to move and react evenly with the color developing agent (CD-3 or CD-4). To help this, the developer contains certain organic solvents or “development aids.”
Styrax in this context:

• Improves gelatin swelling, so the developer penetrates the emulsion more uniformly.
• Helps dissolve and mobilize dye-forming couplers, improving color formation.
• Reduces uneven development and improves color density and balance.
• Also has a mild anti-oxidation / preservative effect, extending developer life.

Important distinction​

This is not the perfume-grade “styrax essential oil.”
In film chemistry, Styrax refers to benzoin resin extract containing benzyl benzoate and related aromatic esters, chosen for its solvent and stabilizing properties.

Summary​

Name	Chinese	Role in Color Developer
Styrax (benzoin resin extract)	安息香树脂	Coupler solvent, gelatin swelling aid, improves dye formation and reduces uneven development

 

[lamerko]

It's probably about sodium sulfate in this case...

 

[Raghu Kuvempunagar]

ChatGPT:

What is Styrax used in Chinese photographic color film developer?

ChatGPT said:​

In Chinese technical literature on color-film processing, the word Styrax (安息香, benzoin resin) refers to a coupler-solvent / gelatin-swelling auxiliary that is added to color negative developer solutions.

Why it is used​

Color film developers (e.g., C-41 type) must allow the color-forming couplers inside the emulsion to move and react evenly with the color developing agent (CD-3 or CD-4). To help this, the developer contains certain organic solvents or “development aids.”
Styrax in this context:

• Improves gelatin swelling, so the developer penetrates the emulsion more uniformly.
• Helps dissolve and mobilize dye-forming couplers, improving color formation.
• Reduces uneven development and improves color density and balance.
• Also has a mild anti-oxidation / preservative effect, extending developer life.

Important distinction​

This is not the perfume-grade “styrax essential oil.”
In film chemistry, Styrax refers to benzoin resin extract containing benzyl benzoate and related aromatic esters, chosen for its solvent and stabilizing properties.

Summary​

Name	Chinese	Role in Color Developer
Styrax (benzoin resin extract)	安息香树脂	Coupler solvent, gelatin swelling aid, improves dye formation and reduces uneven development

Here is how Gemini translates the segment 显定合一浴配方 (三) :
Integrated Bleaching-Fixing-Developing Bath Formula (III)


If Gemini translation is correct, the mysterious Styrax and Styrax is nothing but incorrect translation of bleaching and fixing.

 

[Alan Johnson]

Where to buy Styrax:

ChatGPT said:​

Short answer:
You won’t usually find Styrax sold as a photographic chemical anymore — you’ll find it sold as resin (storax / benzoin) for incense, perfumery, or traditional medicine. The same material is what was historically used in some Chinese soft-working developers.
What to look for:
The correct item is usually one of the following names:

Name on Label	What It Is	Suitable?	Notes
Storax (Styrax benzoin / Gum Benzoin / 安息香 ān xī xiāng)	Resin used in perfume & incense	Yes	Most commonly used in Chinese developer formulas.
Liquidambar orientalis “Storax”	Similar aromatic resin	Yes	Also acceptable if listed as 自然苏合香.
Styrax “Benzoin Siam” or “Benzoin Sumatra”	Perfume-grade resin granules	Best choice	Generally pure and easy to dissolve in alcohol.

The important part is that you want raw resin, not processed incense sticks.

---

Where to Buy​

Online (International)​

Source	Type	Link / Info
Etsy	Raw benzoin resin granules	Search “benzoin resin Siam” or “storax resin”
eBay	Benzoin resin or storax chunks	Many small-batch sellers
Perfumer Supply House / MakingCosmetics / Eden Botanicals	High-purity perfumery resin	Good if you want consistency
Alibaba / AliExpress	Direct from Chinese resin suppliers	Search: 安息香 原料 or 苏合香 树脂

If You Are in China or Near a Chinatown​

Look in TCM / herbal stores, because the resin is still sold medicinally:

• Ask for: 安息香 (ān xī xiāng) or 苏合香 (sū hé xiāng)
• Usually sold in chunks or powder, very cheap.

Also available on:

• Taobao
• 京东 (JD)
• 一亩三分地 Chinese incense sellers

Search term to use:

安息香 原料
苏合香 树脂

---

How It Was Used in Developers​

Styrax was not a developing agent — it was included for:

• Softening grain appearance
• Restraining fog
• Increasing “glow” in warm-tone papers
• Slight tanning effect in some pyro-like developers

Developers didn’t dissolve it directly in water.
You usually make an alcohol tincture first, then add a few drops to working solution:

1 part benzoin resin
5–10 parts 95% ethanol
Dissolve and filter
Then add ~0.5–2 mL per liter of developer.

 

[MattKing]

Essentially, and to put it in a context that @pentaxuser would be likely to appreciate, Styrax might be used to make your wicket sticky.

 

[Alan Johnson]

@xiaruan if still following, Styrax does not sound very important, can it be left out?

 

[xiaruan]

I found a formula for a color monobath developer in a book, which claims to develop and fix color negative film in a single step at room temperature in just 2 minutes. I'm quite skeptical about this, but I currently don't have the means to test it. I'd like to hear everyone's thoughts on this formula.

Monobath Developer Formula

• Water: 750 mL
• CD-4: 4 g
• Anhydrous Sodium Sulfite: 10 g
• Anhydrous Sodium Sulfate: 60 g
• Potassium Bromide: 3 g
• Sodium Hydroxide: 52.5 g
• Sodium Thiosulfate: 25 g
• Add water to make a final volume of: 1000 mL

The book also includes a description of the principles behind this formula, but it seems there are some issues with it as well. However, since I'm not very familiar with color development, I can't pinpoint exactly where the errors lie.
The monobath development and fixation method proposed by the American 3M Company performs development and fixation simultaneously during color development. This process eliminates the bleaching step, leaves no silver residue, and produces satisfactory color images. The main components of the processing solution are color developing agents and fixing agents, and the solution is strongly alkaline (pH ≥ 13.2). Various types of color developing agents can be used in the monobath solution, but CD-3 or CD-4 are typically selected. The fixing agent usually chosen is sodium thiosulfate, but alternatives such as thiocyanate, mercaptosuccinic acid, and thioglycolic acid can also be used.

Excellent results can be achieved when using the monobath method to process various types of film.

The reason why the silver image does not affect the color image when using the monobath processing method is as follows: When silver halide is directly reduced and developed from its solid state, the resulting silver image has high covering power. However, when it is dissolved in the processing solution to form silver ions or silver complex ions, and then reduced and deposited on the latent image, the resulting silver image has low covering power. The monobath processing solution contains fixing agents that dissolve the silver halide particles. Even if the silver image increases proportionally with the dye image, the density of the silver image remains low, allowing light to pass through the silver image effectively. This ensures that the quality of the color image remains unaffected.

The translation I provided corresponds to the earliest two posts I made in this thread. The name of this developer means "Unified Developer-Fixer Formulation for Color Photosensitive Materials."

 

[Alan Johnson]

"Monobath development times vary widely depending on the specific product and film type, with times typically ranging from 3 to 17 minutes for many common films. For example, CineStill DF96 can take 3-6 minutes at 70-80°F (21-27°C), while the development time for Kodak Tri-X is about 16 minutes at 70°F. Since monobaths are one-step solutions that combine developer and fixer, extending the time mainly affects fixing, but it's crucial to follow the manufacturer's instructions for the specific film being developed."

Are there any instructions regarding the temperature and time of development for the UDFFCPM developer?
2 min at room temperature seems rather short.

 

[Raghu Kuvempunagar]

Are there any instructions regarding the temperature and time of development for the UDFFCPM developer?

Time was mentioned for the second and third formula.

Formula for a combined bath with styrax and styrax (Part 2)
...
Note: Use the second formula of the combined bath solution. Rinse for 2 minutes at room temperature, then wash with water and dry.


Formula for a combined bath with styrax and styrax (Part 3)
...
Note: When using this one-bath developer-stabilizer formula, rinse for 4 minutes at room temperature.

The patent I shared earlier that works at the same pH as these recommends a temperature range of 30-40 C.

Are you going to give the monobath a try?

 

[Alan Johnson]

I found a formula for a color monobath developer in a book, which claims to develop and fix color negative film in a single step at room temperature in just 2 minutes. I'm quite skeptical about this, but I currently don't have the means to test it. I'd like to hear everyone's thoughts on this formula.

Monobath Developer Formula

• Water: 750 mL
• CD-4: 4 g
• Anhydrous Sodium Sulfite: 10 g
• Anhydrous Sodium Sulfate: 60 g
• Potassium Bromide: 3 g
• Sodium Hydroxide: 52.5 g
• Sodium Thiosulfate: 25 g
• Add water to make a final volume of: 1000 mL

The above formula is very similar to example 1 of the patent linked by Raghu, excepting that the patent table 1 seems to indicate that the sodium hydroxide should be around 18.4g pH=13.9 to control contrast (gamma=1.1) and thiosulfate is reduced to 19g. Also the patent formula gives the same weights of the components but in 800ml, not 1000ml. Develop 7 min 23C according to the patent. So this modification to the formula of @xiaruan might be considered as a start?

https://patentimages.storage.googleapis.com/e4/5d/4f/2c77d8812c25a8/US3756822.pdf

 

[pentaxuser]

"Monobath development times vary widely depending on the specific product and film type, with times typically ranging from 3 to 17 minutes for many common films. For example, CineStill DF96 can take 3-6 minutes at 70-80°F (21-27°C), while the development time for Kodak Tri-X is about 16 minutes at 70°F. Since monobaths are one-step solutions that combine developer and fixer, extending the time mainly affects fixing, but it's crucial to follow the manufacturer's instructions for the specific film being developed."

Are there any instructions regarding the temperature and time of development for the UDFFCPM developer?
2 min at room temperature seems rather short.

I take you are British, Alan as you last sentence sounds like the classical British understatement

pentaxuser

 

[Raghu Kuvempunagar]

So this modification to the formula of @xiaruan might be considered as a start?

I think it would be. However, the monobath formula might not be have been designed for C41 films. The patent I linked in my earlier post was filed in 1971 whereas C41 process was introduced in 1972 (as per Wikipedia).

p.s. This patent seems to be the 3M patent that the Chinese book mentions which partly explains the closeness of the formulas. Further, Minnesota Mining and Manufacturing Company to whom the patent was assigned later became 3M.

 

[Alan Johnson]

https://patentimages.storage.googleapis.com/e4/5d/4f/2c77d8812c25a8/US3756822.pdf

I tried the formula of example 1 in the Patent with 18.4g sodium hydroxide, developing for the specified 7m 23C. Film was a strip of 1yr out of date Ektar 100, EI=100.
The result was completely opaque negatives apparently covered in black silver. These were bleached for 5 min and fixed but remained opaque.
The sodium thiosulfate in the solution was increased from 19 to 125 grams per 800ml and a second strip developed 2min 22.5C. Again the negatives were opaque to my scanner but on bleaching and fixing a very thin image was visible. This was scanned with the setting for Ektar 100 with the result attached.

It does seem that the time of 2 mins at room temperature given in the book mentioned above is about right. It may be that the formula given in the book will give better results than the patent formula which necessitated addition of bleach and fix steps and appears to be not a satisfactory monobath.

 

[afriman]

https://patentimages.storage.googleapis.com/e4/5d/4f/2c77d8812c25a8/US3756822.pdf

I tried the formula of example 1 in the Patent with 18.4g sodium hydroxide, developing for the specified 7m 23C. Film was a strip of 1yr out of date Ektar 100, EI=100.
The result was completely opaque negatives apparently covered in black silver. These were bleached for 5 min and fixed but remained opaque.
The sodium thiosulfate in the solution was increased from 19 to 125 grams per 800ml and a second strip developed 2min 22.5C. Again the negatives were opaque to my scanner but on bleaching and fixing a very thin image was visible. This was scanned with the setting for Ektar 100 with the result attached.

It does seem that the time of 2 mins at room temperature given in the book mentioned above is about right. It may be that the formula given in the book will give better results than the patent formula which necessitated addition of bleach and fix steps and appears to be not a satisfactory monobath.

No surprises there. Since the formula was apparently intended for older films, with which it might have yielded acceptable results, it's probably a non-starter for C41. Thanks for trying anyway!

 

[Eric Klingberg]

I tried the formula of example 1 in the Patent with 18.4g sodium hydroxide, developing for the specified 7m 23C. Film was a strip of 1yr out of date Ektar 100, EI=100.

The other patent from 1980 corrects some of the earlier ones. It specifically names Eastman Color Print Film type 7383 as appropriate for their formula. ECP films have specific characteristics, so trying something like Kodak 2383 may yield better results, but it's super slow. If you go that route, you'd also need to use filters since ECP film is intended for tungsten light. FPP Sun ISO 1 is daylight balanced copy film, so that may be better. For C-41, maybe Aerocolor IV (Kodak 2460) or Ilford Phoenix would be slightly better since they have a clear base? I actually like weird colors like your photo, so for creative photography I'd call this a win!

 

[Alan Johnson]

Thanks for comments. I would like to get wacky colors from C-41 films in a genuine monobath at room temperature and the formula posted by @xiaruan seems to offer the best prospects (it is Part 2 in the translation).

 

[xiaruan]

Is it possible to achieve better results using CD3? CD3 development appears to be less affected by temperature.

 

[Raghu Kuvempunagar]

For wacky colours one could perhaps consider doing what 2F/2F and PE discussed here and here without needing a monobath.

I wonder what would happen if the colour film is first developed in a B&W monobath like Cinestill DF96, rehalogenated and redeveloped in C41 developer. I believe some kind of bleach-bypass effect with wacky colours.

 

[koraks]

Is it possible to achieve better results using CD3? CD3 development appears to be less affected by temperature.

The problem is not so much in the color developing agent; it's in the fact that development is poorly controlled and no developed silver is removed from the negatives.
Using CD3 can be expected to result in even poorer colors on C41 film.

Use this formula if you want to have totally wacky, unpredictable and weird results. If you want normal negatives, use a normal C41 process.

 

[Alan Johnson]

Theory differences:
The translated formulae in post 22 contain sodium hydroxide g/L 25-125, 52.5 and115. The 3M work in the second patent in post 23 claims that best results for dye formation and invisibilty of
developed silver are obtained at a pH about 13.5 to 14.2. Thus the Chinese book favors these high pH formulae.
However, the first patent in post 23 claims this is mistaken. By using a formula that produces more physical development the silver image has only about half the covering power which obstructs the dye image by less. Also the best dye formation is obtained at pH about 10.6.

 

[Alan Johnson]

I tried the formula of post 1 ,Kodak Colorplus 200 EI=100, 2min 21C but although an image could be seen on the negative it was again opaque to my scanner.
This concentration of sodium hydroxide is hazardous so it is advised to research it and take the appropriate precautions.

Next, still using Colorplus at EI 100 I tried a close approximation of example 1 in the first patent, developing for 5m at 31C with the agitation recommended.
Call it Miller Color Monobath or CMM-1
This time the image could be scanned, the result comparing a print-out color checker (top) and an unmodified scan of the monobath print (bottom) is shown in the attachment.
It may be a little difficult to find this result very inspiring.

 

[Raghu Kuvempunagar]

It may be a little difficult to find this result very inspiring.

Thank you Alan for sharing your experience. These monobaths might not be meant for C41 films. Though the first patent doesn't explicitly state this, the films on which the monobath was tesed were Eastman Color Positive Print Film type 5381 and 7383. And any advantages a colour monobath might have offered to large volume film processing in the past don't seem to hold for small volume processing especially in comparison to bleach-bypass process.