EXG1, a minimal Glycin film developer formula

Some time ago I mixed quite a bit of 10% glycin-TEA mixture. ie, 80ml of triethanolamine (clear grade, not yellow) and 10g of glycin. Heated it up and stirred with a magnetic stirrer for probably around an hour and eventually it was all incorporated, then I topped to 100ml of total solution with triethanolamine. I mixed this up for other experiments, but it seemed like glycin wasn't what I needed there so I figured I'd try using it as a film developer. The end product is "EXG1". The formula is as so:

* 800ml water (warm if mixing from powdered glycin)
* 20ml Glycin-TEA 10% (otherwise substitute with 20ml of TEA and 2g of glycin, mixed in last)
* 12g of potassium carbonate (I use 60ml of 20% solution for easy mixing)
* top to 1L of water
* Use as soon as possible, when the proper temperature. Activity will change after 6 hours, maybe less. Do not reuse
* Starting point time for unknown films of 11m at 70F with normal agitation

This formula of course is begging to be modified, similar to D-23, and Glycin-TEA is a great mixture to have on hand anyway, since it is probably more stable than the glycin in powder form. One important thing missing here is the complete lack of sulfite. Glycin stays alive a surprisingly long time with absolutely no sulfite, at least if TEA is present. (TEA can scavenge some oxygen, though not nearly as efficiently) I was still getting paper darkening after 2 days of just leaving a bit of glycin-TEA and water in an open beaker. I'm not sure what exactly I'd want to add to this formula as I'm fairly content with it. It can be quite grainy with T-grain films, so an addition of sulfite as a silver solvent might be helpful there, but I rarely use T-grain films so I haven't bothered.

I've tried this with several films and have been especially delighted when using this to push HP5+. The results are definitely not fine grained, but also aren't overly grainy (aside from T-Max 3200), and yields very sharp results. Similar to Rodinal but without the tendency to have clumpy grain, the grain here is much smoother and to my eyes more attractive and natural. One notable thing is that the grain doesn't seem to get bigger with pushing, though it does get more obvious just due to the contrast increase. Overall tonality is full speed shadows, compensated highlights, and normal to raised contrast midtones.

I made two blog posts giving results including some full resolution "real" shots and times, but I'll also attach some example pictures here for the people that don't want to click through

https://grainy.vision/blog/exg1-a-bare-bones-glycin-film-developer
https://grainy.vision/blog/exg1-for-pushing-film

HP5+@1600 (20m development time)




FP4+@125 (11m development time)



T-Max 3200@3200 (20m development time)



FP4+@400 (19m development time)


Acros 100@400 (19m development time)

My own immediate inclination is that you've essentially made a Rodinal-ish developer, rather than D-23-ish. It would probably be worth testing variants with equivalent substitutions of P-Aminophenol & Metol & seeing if they can be made to match - my own suspicions tend towards Glycin not being the magical component people claim, but rather its lower reduction potential than its brethren allows for a wider margin of error in mixing etc rather than adding more Metol or whatever. Possibly worth trying a hydroxide activator and seeing what that does too - what was the pH of the developer at working strength?

Another possibility is to use thiocyanate as a grain solvent - it seems that the flat grain emulsions want a degree of solvency for their high iodide emulsions to hit an optimal balance of fine grain and high sharpness.

There is plenty of silver solvent in there (TEA is a weak silver solvent), which makes the developer quite similar to Hubl's paste. However, since you don't appear to have added any sulfite, you may have created a self restraining developer. While HQ goes ballistic (photographically speaking), if you starve it of sulfite, whereas Metol just becomes very slow. Glycin, which is quite similar to Metol, may behave just the same. Your FP4@400 example does show very controlled highlights, so do your HP5+ examples.

PS: if you don't believe, that TEA is a silver solvent (I didn't either), I suggest the following experiment: take a small beaker filled half way with deionized water, put in some Silver Nitrate and some Sodium or Potassium Chloride. Watch precipitation of Silver Chloride. Then add TEA and watch the precipitate dissolve again.

Rudeofus said:

There is plenty of silver solvent in there (TEA is a weak silver solvent), which makes the developer quite similar to Hubl's paste. However, since you don't appear to have added any sulfite, you may have created a self restraining developer. While HQ goes ballistic (photographically speaking), if you starve it of sulfite, whereas Metol just becomes very slow. Glycin, which is quite similar to Metol, may behave just the same. Your FP4@400 example does show very controlled highlights, so do your HP5+ examples.

PS: if you don't believe, that TEA is a silver solvent (I didn't either), I suggest the following experiment: take a small beaker filled half way with deionized water, put in some Silver Nitrate and some Sodium or Potassium Chloride. Watch precipitation of Silver Chloride. Then add TEA and watch the precipitate dissolve again.

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Ah, yes - there was something I couldn't quite put my finger on regarding TEA & for the life of me I couldn't remember if it had a solvent effect. Would also explain the 'cleaner' grain than Rodinal.

Interesting stuff!

You might be aware of Jay Defehr's GSD-10 developer which uses only Glycin, Carbonate and Sulphite. A litre of GSD-10 1:10 working solution contains 2g of Glycin, 15g of Carbonate and 10g of Sulphite. Just wondering how your formulation compares with GSD-10 which is known to be a good semi-stand or stand developer.

Raghu Kuvempunagar said:

Interesting stuff!

You might be aware of Jay Defehr's GSD-10 developer which uses only Glycin, Carbonate and Sulphite. A litre of GSD-10 1:10 working solution contains 2g of Glycin, 15g of Carbonate and 10g of Sulphite. Just wondering how your formulation compares with GSD-10 which is known to be a good semi-stand or stand developer.

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It's on my list of formulas to try out, but in general I don't care much for stand development outside of a few special circumstances. I tend to prefer higher contrast levels and stand development is quite boring in that regard, despite the benefits like exposure latitude and edge effects.

Lachlan Young said:

My own immediate inclination is that you've essentially made a Rodinal-ish developer, rather than D-23-ish. It would probably be worth testing variants with equivalent substitutions of P-Aminophenol & Metol & seeing if they can be made to match - my own suspicions tend towards Glycin not being the magical component people claim, but rather its lower reduction potential than its brethren allows for a wider margin of error in mixing etc rather than adding more Metol or whatever. Possibly worth trying a hydroxide activator and seeing what that does too - what was the pH of the developer at working strength?

Another possibility is to use thiocyanate as a grain solvent - it seems that the flat grain emulsions want a degree of solvency for their high iodide emulsions to hit an optimal balance of fine grain and high sharpness.

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Yes, I'd consider it rodinal-ish, but it's of course much more simple containing only 2-3 ingredients depending on how you count. I meant that it's like D-23 in that it's an extremely simple formula that can be further modified.

I know that Glycin is known as "high Ph metol", and most glycin-only developers use a pH >11. The pH of this developer is ~11 (measured with pH paper) and is stable, staying the same level after development is complete. I think using metol instead of glycin would not work well, as glycin has a number of unique effects:

* Glycin, seems to be capable of removing it's own oxidation products, hence why it has such a long life even with minimal preservative. Metol will instead be removed by it's own oxidation products (sulfite will remove them) and hydroquinone of course goes into infectious development, and also attacks itself with the oxidation products
* Glycin is extremely sensitive to bromide. This is responsible for the compensating effect in highlights, and puts it into a more similar class with hydroquinone rather than metol or phenidone
* Glycin is known in some cases to act as a silver solvent. This effect is mostly known when using too much sulfite. I'm unsure if TEA would activate this effect or if there is any effect without sulfite

I've also tried formulating a paper developer using only glycin and adding hydroxide. The results may have been usable for film, but it could not develop to full black with paper even when adding thiocyanate and having a measured pH of ~13. I also used this developer without the carbonate as a stand developer for film. For me it was nothing greatly noteworthy as it was quite low contrast, but it might be something other people like, especially for portraits. The measured pH was 10 iirc and I was able to get box speed with HP5+ with a 50 minute stand process but would prefer it at ISO 200. However, it had some sprocket streaks in the exposed leader, but no apparent effects on the actual image area.

Also, as an evaluation of sharpness and edge effects of EXG1. It seems to be sharp, without clumpy grain (unknown if there is any silver solvent action happening), and with minimal edge effects

Picture of HP5+@1600


100% crop (~40MP) showing grain and edge detail


And a test shot of the no-carbonate stand developer with HP5+@400


And grain detail of that:


Edit: and yes, TEA here is at least capable of acting as a silver solvent. I'm unsure if it does at these concentrations to any measurable amount though. TEA seems to be less understood than most developer components and I've personally done a ton of experiments with it. For instance, with hydroquinone and no sulfite at all, having a high concentration (5%) will keep the hydroquinone alive for several hours, prevent infectious development, and overall make the developer give a surprisingly normal contrast.. Where as HQ with no sulfite nor TEA of course produces only very high contrast results and dies extremely quickly. TEA is known to absorb radicals of many quinones, absorb peroxides (produced by HQ), but I'm unsure if it will also absorb oxidation products or radicals from phenols (ie, glycin, metol, phenidone)

earlz said:

It's on my list of formulas to try out, but in general I don't care much for stand development outside of a few special circumstances. I tend to prefer higher contrast levels and stand development is quite boring in that regard, despite the benefits like exposure latitude and edge effects.

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FWIW GSD-10 is not limited to stand development. According to Jay Defehr: "Any agitation pattern from rotary to stand is practical, and will produce excellent results with the appropriate compensation."
http://gsd-10.blogspot.com/2006/12/introduction.html

Raghu Kuvempunagar said:

FWIW GSD-10 is not limited to stand development. According to Jay Defehr: "Any agitation pattern from rotary to stand is practical, and will produce excellent results with the appropriate compensation."
http://gsd-10.blogspot.com/2006/12/introduction.html

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Honestly the formulas are quite similar, though GSD-10 has an equivalent working solution per liter:

* glycin 1g
* sodium carbonate 7.5g
* sulfite 5g

and sometimes used doubled in strength. For the most part, the common 1:20 dilution is half the strength of EXG1 and seems to be significantly more active. 1:10 (ie, about the same strength as EXG1 but with sulfite) has a recommended time of 7m30s for a 100 speed film which seems quite short considering 11m is what I get for EXG1 with FP4+@125. Maybe the sulfite significantly increases development speed. Overall the tonality is similar but with higher overall contrast and less highlight compensation even with stand development and significantly finer grain in all cases where I can find a comparable. I'm curious of how the actual negatives on the GSD site looks like, maybe he prefers his negatives to be thicker, explaining the brighter highlights. The fine grain is definitely an immediate night and day difference though. I imagine you could make something very similar to GSD-10 from from a half-diluted EXG1 with some additional carbonate and added sulfite. I honestly don't expect that TEA has much effect in EXG1 at the dilutions used. I'll definitely try that next time I use T-grain film. I think T-grain has rather ugly grain in this developer that is too gritty, rather than the smoothness that is produced from traditional grain films like HP5+. I also need to shoot some Tri-X and try it out, but I found that I had ran out when I was last doing some test strips to figure out development times.

edit: also, the site has weird inconsistencies with some developing instructions being "old" GSD-10, and others being "new" GSD-10 that is twice the strength and then diluted to normal. Not sure why it was made so confusing

I was not impressed when I mixed up GSD-10 as after a few months in a nearly full glass bottle it developed a grey precipitate, I guess Glycin must be unstable for long storage in water at carbonate pH. It may be that keeping the glycin in TEA as proposed here it would last a lot longer. I happen to have a solution of glycin in TEA (dont recall the exact concentration) that is about 10 years old, stored in a film canister. On adding some to water with sodium carbonate pH 11-12, it blackened a film leader in a few minutes.The glycin-TEA appears very long lasting.
The ESG-1 formula is not dissimilar to Beutler (glycin replacing metol) without the sulfite , pH 11-12 so it might be a good method of mixing a high acutance developer for occasional use. It is preferable to use 99% TEA, not the stuff with 15% water or 15% diethanolamine, the 99% may be hard to source.

99% is available from The Chemistry Store.
https://www.chemistrystore.com/Chemicals_S-Z-Triethanolamine_99.html

Alan Johnson said:

I was not impressed when I mixed up GSD-10 as after a few months in a nearly full glass bottle it developed a grey precipitate, I guess Glycin must be unstable for long storage in water at carbonate pH. It may be that keeping the glycin in TEA as proposed here it would last a lot longer. I happen to have a solution of glycin in TEA (dont recall the exact concentration) that is about 10 years old, stored in a film canister. On adding some to water with sodium carbonate pH 11-12, it blackened a film leader in a few minutes.The glycin-TEA appears very long lasting.
The ESG-1 formula is not dissimilar to Beutler (glycin replacing metol) without the sulfite , pH 11-12 so it might be a good method of mixing a high acutance developer for occasional use. It is preferable to use 99% TEA, not the stuff with 15% water or 15% diethanolamine, the 99% may be hard to source.

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Yea, TEA in glycin should in theory last nearly forever, like HC-110 and other no-water based developers. It mixes to be a fairly pale yellowish brown color and even keeping it for over a month in a 3/4 empty bottle I've noticed no color change or other problems. Biggest problem is just that dissolving the Glycin in TEA is a pain, best done at 200F, and takes about 1 hour of stirring to get a 10% solution. I think the theoretical max concentration possible is 12%. I think for a high acutance developer with strong edge effects you'd probably want to use a much less stable alkali, like say hydroxide but still adjusted to 11-12 pH. Then the alkali would locally exhaust during development, causing edge effects. It'd of course probably cause other effects too though.

juan said:

99% is available from The Chemistry Store.
https://www.chemistrystore.com/Chemicals_S-Z-Triethanolamine_99.html

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I got my TEA from photographer's formulary. According to their product codes it's 99% and sourced from Sigma. I've bought TEA in the past from Artcraft, but it was of unknown purity and yellow.

Any thought of adding metol to make something like FX-2?

juan said:

Any thought of adding metol to make something like FX-2?

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If metol was added then sulfite would also be needed to prevent the metol from slowing down development (sub-additive without sulfite). In addition metol is not soluble in TEA.

I actually have a formula somewhat similar to FX-2 called GVK1 which uses fairly small amounts of metol, glycin, and carbonate to get the acutance developer effect, but also including a rather large amount of TEA in the working solution which tends to round off the grain a little bit and provide a buffer. End result is high sharpness but grain that's about comparable to D-76, and much finer grain appearance when pushing. The tonality is really quite nice and the way the developer behaves is rather interesting. Basically the longer you let it go the finer the grain, and higher overall density scale, but contrast doesn't actually increase a whole lot since shadows and highlights tend to develop in lock step with each other. Using this effect, it's possible to aim for a higher "shadow dmin" to get away from the grainy blacks that tend to occur whe shadows are very close to dmin, without highlights running away too much. It's a superb developer for pushing and still producing negatives that will print with good results at grade 2-3. However, unlike FX-2, it is not suitable for stand development (too much highlight development, not enough shadow development)

It also is the only "universal" developer I've seen behave like it does. Using the same dilution, appropriate results can be obtained on paper at 5m (deep brown blacks, olive-brown midtones, increased highlight detail compared to Ansco 130), very high contrast ortho litho film at 6m (pictorial moderate contrast at ~3 ISO), slow films at 10m, high speed films at 15m, and pushed films at 20+m. The formula for GVK1 along with some sample pictures are posted here: https://grainy.vision/blog/gvk1

Example "positive print" onto ortho litho film using GVK1 as the developer attached

Both of these developers look very interesting! Excellent results you've gotten with both, as well.