SPP Saidane's Print Process

imgprojts · May 29, 2025

For anyone who hasn't watched his videos:

Habib Saidane developed a simple formula based on Ferric ammonium citrate to replicate the Gum bichromate process.

He mixes a certain amount of CMC carboxymethylcellulose, gum Arabic, water and FAC to make an emulsion which you then mix with a pigment to create a sensitized coating on watercolor paper.

I've tried and tried to replicate the process using ~380nm -390nm uv sources but so far not much of a success but I though to maybe share some experimental results. I'm not a chemist and I do this as a hobby trying to not learn much more than necessary. I am an opto mechanical engineer, but again don't intend to do much more than helping pass the word and experimenting with whatever I can find.

imgprojts · May 29, 2025

As a first thing to share:

Making CMC from powder is not a simple hand mixing. Do your mixing, let it sit for an hour and come back and mix some more. Do that a few times and let it sit overnight. Its really viscous stuff and I think its the same stuff I used to put on my hair to style it when I was a kid.

Saidane has stated that gum doesn't harden by itself but CMC by itself can work. I personally have done some experimenting and found that both can harden via FAC + UV, but both remain dissolvable in water or 0.3% peroxide water.

I added a couple of grams of Sodium Benzoate to the mix when I first mixed my current batch almost the same week Habib put up the first video. So its been a few months? And the stuff is still nice and clear. Sodium Benzoate is supposedly a weak photo initiator, so that's why I had it around to try. It is used as food preservative so that's why it made sense to try. Without it, the CMC developed mold after a week in a closed glass jar. Habib has since changed to dry mixing in small batches. But the liquid should work too.

Finally, I found out yesterday that if you add more pigment and CMC than necessary it actually dissolves the exposed areas first leaving you with a positive rather than a negative of the image. Yet the real problems I've found are that the stuff will dissolve completely if you just develop it in 0.3% peroxide and continue to keep it submerged. Drying, the image runs and becomes not an image. I'm certain I'm doing all sorts of incorrect stuff. But one thing I've done so far is to warm up the peroxide before developing per Habib's instruction.

imgprojts · May 29, 2025

Since giving up on actually making an image and focusing solely on trying to make the process work, I've resorted to using a simple 25w LED lamp to experiment on small pieces of water color paper. I use coins and washers to make a shadow image to develop. Here's an example of the negative images I've been able to make and the look of it before dunking it in peroxide.

imgprojts · May 29, 2025

imgprojts said:
Since giving up on actually making an image and focusing solely on trying to make the process work, I've resorted to using a simple 25w LED lamp to experiment on small pieces of water color paper. I use coins and washers to make a shadow image to develop. Here's an example of the negative images I've been able to make and the look of it before dunking it in peroxide.

And here is a positive image

imgprojts · May 31, 2025

For your and my info in the future, I got the recipes below:

On the first video:
he makes:
1) 100ml of 2% CMC so a total of ~2g in 100ml liquid
this mix is made in 60C water and you mix it until you get tired and then just let it rest overnight.

He says the Gum Arabic is for emulsifier and binder both of which I highly doubt are actually needed in CMC but alright...
2) get 400ml of water + 200g GA and mix. Add a preservative

3)Ferric Ammonium Citrate:
Mix 25g in 100ml water
Add a preservative

4)Developer 0.3% hydrogen peroxide
9 parts water to 1 part H2O2 @3% makes 10 parts of 0.3% H2O2

Emulsion Mix:
2parts 2% CMC
1part GA
1part FAC

For 100ml:
50ml CMC or 1g
25ml GA or 12.5g (reduced in the second video)
25ml FAC or 6.25g (reduced in the second video)

The recipe on the 2nd video:
with dry ingredients is:

For 100ml:
1gr CMC or 1gr Methylcellulose (powder)
10gr Gum Arabic (powder)
5gr Ferric Ammonium Citrate (powder)

100ml of distilled water.
Directions:
a) Expose in warm temperature environment 20°C or better
b) Develop in 0.3% Hydrogen Peroxide at around 35°C
c) Rinse in warm water at around 35°C

imgprojts · May 31, 2025

Per one of the AI tools:

Compound | Molecular Weight (g/mol)
--------------------------|-------------------------------
Carboxymethyl cellulose | 17,000–800,000 (polymer avg.)
Ferric ammonium citrate | ~368
Ferric ammonium oxalate | ~285
Gum arabic | 250,000–600,000 (polymer avg.)

I tried asking what if any reaction there would be using UV to expose the mix.
According to this AI there would be none with either or both ingredients, CMC or GA. However I asked about adding Sodium Benzoate because of some research and it lead me to this doc:

https://ri.conicet.gov.ar/bitstream...ro.a11ce4b8-0138-46d8-8488-d845048eb28a_D.pdf

which says that indeed ther would be a UV reaction using that. It also suggested trying ammonium persulfate, but that seems too dangerous to have at home.

imgprojts · May 31, 2025

LOL! Holy smokes! Okay, I had Sodium Benzoate around since I was playing around with CMC and I totally dismissed it as photoinitiator previously after doing a variety of tests. But this time I simplified the test. Sam emulsion without SB will just dissolve. SB makes it even have Carbon transfer-like relief. and the edges are sharp, not runny. Previously I had added SB in tiny amounts because it would bubble a lot when adding FAC.

imgprojts · May 31, 2025

Wait up....that's a really strong positive image! What?? I didn't even realize it until just now. I was expecting to put the coins on the the paper, expose and then get a black paper with little round holes. instead it looks like the UV make the exposed parts dissolve away so this would be a positive working emulsion. Well I'm going to let this sample dry overnight and then tomorrow morning my plan is to make a different color and see if I can get the color on without ruining the image below. Then I'll try an image.

xiaruan · May 31, 2025

I tried this method. After adding hydrogen peroxide, there would be an image. However, during the subsequent rinsing process, all the pigments would be washed away.

imgprojts · May 31, 2025

xiaruan said:
I tried this method. After adding hydrogen peroxide, there would be an image. However, during the subsequent rinsing process, all the pigments would be washed away.

That was exactly my problem. But now if you add sodium benzoate it seems to make unexposed CMC insoluble while exposure CMC seems to dissolve fast.

imgprojts · May 31, 2025

I was able to create images with other colors and can confirm that covering one color with a new brushed on coat doesn't dissolve the first layer. That said, there are issues. I made this red color image and quite a few test images in other colors and various combinations of CMC, Arabic Gum, Ferric Ammonium Citrate, Sodium Benzoate, Citric Acid, Sulfamic Acid, Ferric Chloride, peroxide, HCL etc. I started identifying stuff that seems to work and stuff that doesn't. So what I have left is:

Mix:
1 vol of 2%CMC
1 vol of pigment
1 vol of sodium benzoate
1 vol of Ferric Ammonium Citrate

Develop in warm (25 to 35C) 0.3% hydrogen peroxide

Expose for 3 minutes to get the positive image ( exposed stuff dissolves away) or 16 minutes to get a negative image (exposed stuff stays, everything else dissolves). And this is where I am at. Not sure exactly why it works how it works.

What am I using? (all is from amazon)

1) 9oz CMC Powder, 100% Pure Food Grade CMC Powder, Tylose Powder for Fondant, Ice Cream, Cake, Yogurt, Candy & Gum Paste, Premium Carboxymethylcellulose Food Thickener and Moisture Retainer
Brand: Vividye

2) Bluebird Premium Poster Paints 3.4 Fl Oz / 100ml Set of 6 - Vibrant Primary Colors for Stunning Artwork and Creative Projects
Visit the Bluebird Store

3) Spicy World Sodium Benzoate 8 Oz - 99% USP/FCC Grade, Additive and Preservative
Brand: Spicy World

4) Ferric Ammonium Citrate(Green),for Cyanotype(500g/17.6oz)
Visit the EASTCHEM Store

imgprojts · May 31, 2025

So you either get a positive by exposing for 3 minutes or a negative by exposing longer like 16 minutes. I'm not fully sure what is happening but here are images done with the same batch and different exposures:

imgprojts · Sunday at 11:32 AM

Okay...The positive image was not due to less exposure. I just tested a new batch and it just floats away at 3minutes. This was CMC only. Maybe Gum Arabic did play a role in this. I just realized that I changed the pigment too on the test this morning. I added graphite to the poster color. hmm. So many variables. at lest though, it seems that the negative working part was constant in my last experiment.

imgprojts · Wednesday at 9:50 AM

Moderate success this morning:

~2g of 2%CMC (tiny spoon)
0.6g of dry PVA
1 spoon diy carbon
1 very tiny spoon sulfamic acid (makes it a foam with lots of bubbles, maybe not needed, I used graphite which is basic so I thought to add acid)
1.5g FAO
2ml water (I feel like this should be more because it was a little hard to spread)

Mix and heat in microwave for 5-12 seconds. Exposed using UV 365nm (supposedly) LED strip for 3 minutes. I will try making an image with my DLP projector later today. This formula brings in several ideas: 1) Ferric Ammonium Oxalate/citrate will polymerize PVA, Sodium Bensoate too but at angrier UV wavelengths. Mixing PVA with CMC + UV + photosensitizer -> polymerization will happen between both ingredients according to this paper:
https://ri.conicet.gov.ar/bitstream...ro.a11ce4b8-0138-46d8-8488-d845048eb28a_D.pdf

I had absolutely no trouble applying this mix and developing it. I used 0.3% H2O2 spray like Habib does in some of the videos, but then I just decided to dunk it in a cold bath of H2O2 because it didn't just dissolve like all my tests before. the development took between 2 to 3 minutes. This puts it in a good usable range. I noticed that my poster paint was bubbling with the addition of acids so I stopped using that for this experiment. I'm going to use mica powder colors instead. that way I don't have to worry about the powder messing with the chemistry. I'll continue testing. This looks really really nice to work with, super safe materials, plus vegan or very close to vegan, not sure if PVA and mica are vegan or not.

imgprojts · Thursday at 10:01 AM

Finally and image! At first after exposure (30 minutes on the 3000lm normal light projector) you see a faint image. It gets revealed with the peroxide spray. Wait about 30 seconds before developing in tap water. The peroxide starts the polymerization since the image was dry during exposure and reactive stuff is awaiting there. You will see the image stained in ugly iron oxide looking stuff. Finally a quick wash in cold tap water takes away all the un exposed stuff. For normal UV, I expect this exposure to take 3 minutes as in my own UV exposure experiments.

imgprojts · 2025-06-06T02:15:16-0400

Indeed, you can do tricolor. I had nothing to do (other than what my wife wants me to work on next). I ended up stacking 7 layers just to see what happens. The top one is a cyanotype. The bottom one is a bright neon pink.

I simplified the recipe.
1) mix CMC with water at 2% let it sit overnight (trust me, just mix it enough and go to bed). Add some Sodium Benzoate as preservative. Almost 3 months and the stuff is clear)

2) mix PVA at 5%. I saw a YouTube video where a lady demonstrated a mix that was already a year old.

Now mix 2CMCs with 3 PVAs. This gives you a basic goop. Then just add 2 volumes of Ferric ammonium oxalate and a 10th of a volume of a non chelating acid like sulfamic acid or oxalic acid. Finally however much pigment you want. I'm using 1 volume of mica pigment.

Expose for however much exposure you need... Probably around 3 minutes. Then spray with 0.3% peroxide. Finally wash in a citric acid bath ~pH 4. You can just do tap water washing but as you can see my first image had this homogeneous yellow stain. The citric acid keeps ferric ions in solution so you can wash them out.

I really have no clue what I'm doing with the color separation using Gimp. But I'll figure it out. I can see that this process can give some really interesting looking color. So I'm going to see if I can make a decent print of some sort. Its probably garbage, but I'll be happy if I can make something less awful than this.

imgprojts · 2025-06-07T09:27:36-0400

xiaruan said:
I tried this method. After adding hydrogen peroxide, there would be an image. However, during the subsequent rinsing process, all the pigments would be washed away.

with the latest formula here the stuff stays solid during development. I stop development within a couple of minutes because it seems to clear quickly. I do notice that it keeps slowly dissolving, so longer than that just means you'll get a lighter image. I develop with d DLP projector that offers some UV but not that much. It seems to have a sweet spot at 30 minutes to get the same results as a 3 minute development using a UV light. One of my goals is to replace the projector light with a UV LED. But regular exposures should be around 3 minutes. in fact the test coupons for this recipe stayed nice and solid even in hot water.

i'm still adjusting it. For example, PVA transmits UV very well, but CMC almost completely blocks it. And there are other weird things I've observed when exposing CMC+PVA+NewCyanotype (very fast) It initially goes fully blue, it then slowly changes into the expected result. There must be some interesting chemistry happening when wet. When dry, the film is very thin so I assume that is why in the mix I am still able to expose the sensitizer. It will probably be faster with less CMC.

FotoD · 2025-06-07T11:12:30-0400

What is the reasoning behind using CMC?

When an emulsion of CMC + FAC/FAO is exposed to UV and then developed in H2O2, the unexposed parts will be cross-linked and the exposed parts will wash away. It seems to me that is counter to what you want to achieve?

But you are getting an image, so maybe you are on the right track and I just don't get it.

imgprojts · 2025-06-07T11:24:45-0400

FotoD said:
What is the reasoning behind using CMC?

When an emulsion of CMC + FAC/FAO is exposed to UV and then developed in H2O2, the unexposed parts will be cross-linked and the exposed parts will wash away. It seems to me that is counter to what you want to achieve?

But you are getting an image, so maybe you are on the right track and I just don't get it.

I've since found a paper showing that PVA crosslinks with CMC. I started with Sodium Benzoate, which acts as a photoinitiator at high energy UV wavelengths. That actually seems to make an image but its too slow. But then I realized that FAC could do the same thing, only when I tried it totally coagulates CMC on contact. You gotta continue mixing like Habib does in the experiments. Then I asked my friend Chato last name Geepeetee and it suggested that FAO reacts strongly with PVA. I literally put the two ideas together and gives something that seems to work. I got the PVA on Thursday. I haven't tested it by itself. But very noticeably, a very tiny amount of CMC greats this very thick goop which helps coating thickness. Adding a little sodium benzoate makes whatever mix into a thick foam which is something that I've used before when using the new cyanotype formula with it. It makes a thick yellow foam/paste that makes an almost photographic cyanotype emulsion. I'll probably do a video on that because its an interesting effect and I really don't know exactly how it works.

SPP Saidane's Print Process

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