Diffusion Transfer Printing ("Polaroid" peel-apart) recipes

[Qebs]

alecrmyers, the easiest method is to get something like you suggested, I believe it was 3mil tape, and just have it arranged so that the print receives the tape, and the negative film rides the rails. No top rail no bottom rail. It will take extensive cleaning after each use of the motorized roller. When I start doing high volume work or have a budget because it's fine art or commercial assignment/commission, I'll hire an assistant.

 

[alecrmyers]

Just for clarification, the process I’ve been working on most recently and with which I’ve had the most success doesn’t use rails at all. I’ve previously described it as a “contact” process, of which one advantage is that the (cheap) rubber pressure rollers in a laminating machine work well.

If you’re trying to emulate the Polaroid process exactly (I’m not) then you will need rails and finely engineered rollers like the chrome ones you’ve sourced. The bearings for the rollers and the carriage for the bearings might need suitable upgrades too. So that’s why I’m curious and keen to know how well you get it to work.

 

[Qebs]

Hey, concerning fading, I asked the polaroid subreddit, and a nice human being named thinkbrown replied with this:

~~~~~~~~~~~~~~~~
https://www.photrio.com/forum/threa...-printing-polaroid-peel-apart-recipes.205991/ this is probably the broadest collection of info on early polaroid I'm aware of, including a bunch of reproductions of early patent formulas.

https://www.photrio.com/forum/threads/whats-in-a-polaroid-print-coater.37780/ this includes some more specifics on the coaters, including some input from Ron Mowrey who was a chemist at Kodak.

https://archive.org/details/photographyitsma001646mbp Neblette touches on coating in the chapter on diffusion transfer but doesn't say much beyond neutralizing any residual reagent and protecting the print from atmospheric contaminants.

Based on what we do know my guess (noting that I'm definitely not a chemist) is that the acetic acid is present to neutralize any residual processing fluid and the zinc acetate is there as a sulfur sequestrant.


I just checked neblette 7th edition which has the relevant patent for the coater: https://patents.google.com/patent/US2719791A/en

~~~~~~~~~~~~~~~~

I'm thinking a test solution would be to use an airbrushing tool and spraying on the msds listed chemicals, then when that dries, spray on from a spray can some sort of lacquer.

 

[thinkbrown]

Hey, concerning fading, I asked the polaroid subreddit, and a nice human being named thinkbrown replied with this:

Guess someone hasn't read the entire thread

 

[benjschneider]

I am fascinated by your efforts and the results of your exploration into this process! I am a new member and was looking for information on making paper negatives. I'm now thinking of the esthetics of your process in making original artwork, and using larger cameras, like Polaroid once did. Have you tried lens filters to improve the contrast of your images? I once read that a yellow-green filter much improves the tonal vales of a Ilfospped negative in daylight. The ISO of 3 was recommended as a starting point.

I would very much like tp hear more from you. Ben

 

[alecrmyers]

For the last couple of weeks I've been working very hard on analogues of Polaroid's coaterless chemistry, using cellulose acetate instead of silica sol as a substrate.

I've achieved some successes, but there's still some way to go to get results as good as those I get with the silica (print coater analogue) preparations.

I'm going to take a break from the cellulose acetate (and go back to working on silica) so in case I fall under a bus, here's a brief summary of the best I've done so far.

Also I want to acknowledge the ongoing help and support from two retired Polaroid engineers who worked on developing and improving the Polaroid products; it's been invaluable to hear how things worked there, and they've made many valuable suggestions which I've followed up as assiduously as possible.

Just for the record keeping, and in case anyone wants to follow along, here's a recipe for a CA based paper, and accompanying developer.

CA base: in 80g ethyl acetate / 20g methanol, dissolve 4g cellulose acetate (DS 2.2 I think, but not critical)

Paper coating: To 5g of this base add 2 drops 1% NaS, under stirring, then 1 drop 1% Palladium Chloride (dissolved in weak hydrochloric acid)

Coat with 10 micron coating bar. Uses about 1ml per sheet, so about 6 sheets per 5g preparation.

Hydrolysis solution: in 80g methanol, 20g water, dissolve 5g KOH

when paper is dry (less than a minute) overcoat with one pass of a 1 micron coating bar. Half a ml per sheet is plenty.

Developer much as before, with reduced uracil:
25g 2.5-5% CMC (at your choice), 5g KOH, 300mg aminothethylethanolamine, 2g diethylhydroxylamine, 0.35g uracil, 50mg Metol, blend well

Film: Fuji HR-U as before, at an EI of about 100.


Results look like this:

The tonality is variable (and very hard to control) with Dmax a long way below what I can get with silica. On the positive side the prints don't appear to need washing as there's no stain and no salting.

I've been working very hard to find accessible and effective toning agents to add to the developer, but there's nothing to report on that front. If anyone wants to experiment try looking for heterocyclic sulphur-containing compounds, like thiouracils etc.

The CA based images I have from the spring and summer haven't faded at all, so I think these may fare better on display than some of the silica based images.

On the subject of fading, I reviewed my notebooks and while all the silica based images I have on the wall from the summer have faded, the ones that are in my book are as black and dark as they day they were produced. So I"m going to look into that.

 

[Qebs]

Thanks so much for sharing this Alec!
I asked chatgpt/deepseek for advice and this is what is spat out.
Anything interesting here?
Oh and I'm looking for a source for the chemicals locally, I'll post for others in the Toronto/Ontario Canada area.

This forum post is very credible, and it also explains a lot of what you’re seeing. What they’re struggling with (low Dmax, unstable tonality, receiver-dependent behavior) is exactly where sulfur chemistry historically entered Polaroid’s toolbox.
I’ll answer your question directly first (specific sulfur-containing compounds), then explain why some work and others don’t, and finally how to use them without wrecking DTR balance.

---

1. What sulfur compounds actually make sense here​

You’re not looking for generic “sulfur reducers”. You want soft, silver-affinitive, heterocyclic sulfur ligands that:

• Preferentially bind metallic silver nuclei
• Slightly slow highlight reduction
• Deepen image silver (higher Dmax)
• Improve image stability (anti-oxidative)

Best first tier (accessible, proven chemistry)​

Thiourea​

(NH₂)₂CS

• Classic silver toner / intensifier
• Strong Ag–S affinity
• Can deepen blacks dramatically
• Dangerous if overdosed → bleaching or fog

Typical DTR-scale use:

• 5–50 mg per 25 g developer
• Start at 10 mg
• Dissolve separately, add last

Too much will:

• Kill highlights
• Cause sulfur fog
• Create brownish blacks

---

Thiouracil (2-thiouracil, 4-thiouracil)​

This is exactly what the forum author hints at — and for good reason.

• Structurally analogous to uracil
• Sulfur replaces oxygen → stronger Ag binding
• Acts as:
  • Mild toner
  • Development moderator
  • Silver nucleus stabilizer

Recommended approach:

• Replace 5–20% of uracil with thiouracil
• Example:
  • 0.30 g uracil
  • 0.05 g thiouracil

This keeps diffusion chemistry intact while improving Dmax.
This is one of the most Polaroid-like moves you can make.

---

Thiohydantoin​

Less common, but excellent:

• Similar role to thiouracil
• Slightly weaker than thiourea
• Much safer tonally

Use at:

• 10–30 mg per 25 g developer

---

Second tier (more subtle, more control)​

2-Mercaptobenzothiazole (MBT)​

Very interesting compound.

• Strong silver complex former
• Used historically as:
  • Anti-fog
  • Image stabilizer
• Adds cold, neutral blacks

Use very carefully:

• 1–5 mg per 25 g developer
• Alcohol pre-solution recommended

This is closer to engineering chemistry, not casual darkroom use.

---

Thiazolidine-2,4-dione​

• Sulfur heterocycle
• Similar behavior to uracil but softer
• Good highlight control

Good for CA systems where silica isn’t buffering diffusion.

---

2. What not to use (important)​

Avoid:
Sodium sulfide
Thiosulfate (fixer behavior, destroys DTR)
Sulfite (you already have reducers)
Simple mercaptans (smell + fog)
These break the diffusion equilibrium rather than tune it.

---

3. Why sulfur helps specifically in CA systems​

Silica receivers:

• Trap silver physically
• Provide nucleation sites

Cellulose acetate:

• Chemically inert
• Relies entirely on chemical anchoring

Sulfur compounds:

• Create Ag–S surface complexes
• Act as pseudo-nucleation sites
• Replace what silica was giving you mechanically

That’s why:

• CA images fade less
• Dmax is harder to reach
• Tonality is unstable without sulfur

---

4. How to introduce sulfur without chaos​

Golden rule​

Sulfur belongs in the developer, not the receiver.
Receiver sulfur causes:

• Silver scavenging
• Image spread
• Highlight collapse

---

Safe experimental ladder​

Try one at a time, in this order:

1. Replace 10% uracil with thiouracil
2. If blacks still weak: add 10 mg thiourea
3. If highlights still run: add 1–2 mg MBT
4. If muddy: reduce sulfur by half, not alkali

---

5. Why Polaroid never published this​

Sulfur chemistry:

• Smells
• Ages unpredictably
• Is batch sensitive
• Interacts with exposure scale

It was absolutely used, but buried under trade secrecy and process control.
What you’re doing now is essentially re-discovering the last 10% Polaroid never wanted hobbyists touching.

---

If you want, next we can:

• Design a CA-specific DTR developer
• Translate this into paper-negative compatibility
• Or model how sulfur shifts your exposure curve

Just tell me which direction you want to go.

 

[alecrmyers]

Thanks so much for sharing this Alec!
I asked chatgpt/deepseek for advice and this is what is spat out.
Anything interesting here?

To paraphrase Johnson, that AI response is both original and correct. Unfortunately what is correct is not original and what is original is not correct.

The language model is designed to feed back to you things you already know with other stuff linguistically blended in such a way as to sound equally authoritative. But there is enough obviously hallucinated content - and enough obviously relevant content that a knowledgeable commentator would mention that the AI doesn't - to call into question the entire answer. AI is an extremely good mimic. If the answer to the question you're looking for isn't already written online somewhere, it cannot use reason, logic or imagination to create one. But it can make you think it can.

Bottom line is - please go ahead and try the suggestions in your own post, and let me know how it works. Hopefully, very well.

 

[analogwisdom]

I am going to start trialing coating my own positives soon. The coater bar has finally arrived from China, and I'm just waiting for my local chemistry supplier to receive the order of chemicals I placed.

I got some Adox Art Baryta uncoated paper to test with. Fingers crossed!

 

[alecrmyers]

Fabulous. Looking forward to hearing how it goes.

 

[analogwisdom]

I've got some Dimezone-S to try out as the super additive developer. Any suggestions on amount to use compared to Metol?

 

[alecrmyers]

Try 50mg, and let me know. I'm trying to order some Dimezone S myself.

Try also without any second developer.

 

[analogwisdom]

Try 50mg, and let me know. I'm trying to order some Dimezone S myself.

Bellini Dimezone S 10 Grams

Bellini Dimezone S 10 Grams - Bellini Foto has been operating in the field of photo chemistry since 1988. They want to preserve and pass on the precious experience of the analog world. Bellini is one of the only photo chemical companies…

www.freestylephoto.com

Not sure if they'll ship it up to you.

Try also without any second developer.

My first batch of developer had only TBHQ - that worked well on Polaroid Type 55.


Everything is here except the granite plate and my chemicals from the local supplier. Itching to get started on positive experimenting.

 

[alecrmyers]

Bellini Dimezone S 10 Grams

Bellini Dimezone S 10 Grams - Bellini Foto has been operating in the field of photo chemistry since 1988. They want to preserve and pass on the precious experience of the analog world. Bellini is one of the only photo chemical companies…

www.freestylephoto.com

Not sure if they'll ship it up to you.


My first batch of developer had only TBHQ - that worked well on Polaroid Type 55.


Everything is here except the granite plate and my chemicals from the local supplier. Itching to get started on positive experimenting.

I'm not sure the granite plate is vital. It was originally important for using a roller to spread the developer with rails; I've made some adequate papers without one. That's helpful because I want to scale up to LF, and a large surface plate is extremely heavy.

 

[analogwisdom]

I'm not sure the granite plate is vital. It was originally important for using a roller to spread the developer with rails; I've made some adequate papers without one. That's helpful because I want to scale up to LF, and a large surface plate is extremely heavy.

I see. Well, I got one on Amazon (as you said earlier in the thread, where would this project be without Amazon) for $59. RIP to the driver that's delivering an 80lb granite plate.

This is an uncoated baryta sheet with material scrapped from an 8x10 Polaroid negative glued on. I was successfully able to insert it back into an 8x10 sleeve, seal that, and place it into the Polaroid 8x10 holder + withdraw the sleeve. My dummy "negative" stayed in the holder with the tab intact.

The next step is to make up a dummy "positive" and see if it can survive going through the processor with the negative, without the tabs tearing.

 

[alecrmyers]

You won't regret having a surface plate. I think it may give you better results, and if you don't have one you'll be left wondering if you should have got one.

But you can certainly get started without it.

 

[analogwisdom]

Type 804 positive on the left, (uncoated) baryta paper assembled by me with kraft paper on the right. The side rails are polyester tape, 3.5mil thickness. The bottom piece and top plastic pieces were salvaged from a shot Polaroid 8x10 photo. I am going to have a friend 3D print the plastic tabs. I have several dozen of the salvaged bottom pieces, but it isn't a very complicated piece of paper to replicate.

I successfully loaded it into the Polaroid 8x10 holder with my dummy negative, and the sandwich was easily pulled thru the processor (the pod was empty.)

Encouraging progress on this front! Let's hope I'm able to actually coat and get some good transfer onto positives. I'm going to use 8x10 photo paper (Ilford) as my negatives.

 

[alecrmyers]

View attachment 416223
Type 804 positive on the left, (uncoated) baryta paper assembled by me with kraft paper on the right. The side rails are polyester tape, 3.5mil thickness. The bottom piece and top plastic pieces were salvaged from a shot Polaroid 8x10 photo. I am going to have a friend 3D print the plastic tabs. I have several dozen of the salvaged bottom pieces, but it isn't a very complicated piece of paper to replicate.

I successfully loaded it into the Polaroid 8x10 holder with my dummy negative, and the sandwich was easily pulled thru the processor (the pod was empty.)

Encouraging progress on this front! Let's hope I'm able to actually coat and get some good transfer onto positives. I'm going to use 8x10 photo paper (Ilford) as my negatives.

Why not get some 8x10 x-ray film (Fuji HR-U)? It's cheaper than Ilford paper and 7 stops faster.

 

[analogwisdom]

Why not get some 8x10 x-ray film (Fuji HR-U)? It's cheaper than Ilford paper and 7 stops faster.

Good shout, I meant to order some but forgot. I also have some 8x10 HP5 and Tri-X; but I don't want to jump right into using those, especially since I cant assemble the negative sleeve under safelight.

I'm also not sure if the Polaroid 8x10 processor is light-tight... Might need to grab a blanket to throw over it.

 

[analogwisdom]

I sent some developer I made to a friend and this was his result on dried Type 54. This is my latest try using uracil as the solvent, success! There was no superadditive developer (just DEHA), so the film had to be shot at ISO 16 (as opposed to the original 100) to get this result. I'm ecstatic! This is close to perfect tonality for T54.

 

[NedL]

I sent some developer I made to a friend and this was his result on dried Type 54. This is my latest try using uracil as the solvent, success! There was no superadditive developer (just DEHA), so the film had to be shot at ISO 16 (as opposed to the original 100) to get this result. I'm ecstatic! This is close to perfect tonality for T54.

Well done!

 

[analogwisdom]

Here are his first and second attempts on T54, first at box speed (100) then at 25.

 

[analogwisdom]

For those following along at home, here's the recipe for the above developer. (I'm calling this my Developer Type 7).

30g base (15% w/w KOH + 2.5% HEC)
2.2g Uracil
1.2g triethanolamine
1g n,n-DEHA (98% purity)
0.5g Zinc Acetate

I dissolved the Zinc in the TEA. Note the higher concentration of alkali and the switch to KOH (thanks for the advice Alec).

My granite plate came yesterday. Here in Kentucky we're under 12 inches of snow (and still falling) so it's going to be a little while before I get the rest of my chemicals.

 

[alecrmyers]

For those following along at home, here's the recipe for the above developer. (I'm calling this my Developer Type 7).

30g base (15% w/w KOH + 2.5% HEC)
2.2g Uracil
1.2g triethanolamine
1g n,n-DEHA (98% purity)
0.5g Zinc Acetate

I dissolved the Zinc in the TEA. Note the higher concentration of alkali and the switch to KOH (thanks for the advice Alec).

My granite plate came yesterday. Here in Kentucky we're under 12 inches of snow (and still falling) so it's going to be a little while before I get the rest of my chemicals.

Excellent.

Can you comment on the choice and amount of TEA vs AEEA?

 

[analogwisdom]

Excellent.

Can you comment on the choice and amount of TEA vs AEEA?

I wish I could give an answer and be correct. I used it based off of the SDS I shared earlier in the thread, and because you told me to try replacing the AEEA.

I increased the TEA to around 4% because I figured that DEHA is less stable than the DMEHA that Polaroid used, so the increased concentration of TEA would help with stability. I also figured AEEA is too aggressive as a secondary solvent?

I could also be completely wrong and got lucky, I'm learning as I go.