A New Cuprotype?

[nmp]

I've not tested my UV BL tubes, but I haven't used them for months, anyway. The LEDs, despite this shortcoming, are so far superior in terms of sharpness of the prints that I'm probably not going to bother with tubes anymore.

If it ain't broke....

My reason for for rejecting that unit really was the flux I was getting which was no better than my current set-up, trying to bring down cuprotype exposure times. I already spent time/money on building one more with Barrina LED's and that one also gave similar times so at that point I didn't want to make an effort build yet another box which may or may not have been faster. So it went back to Amazon.

:Niranjan.

 

[Bronson Dugnutt]

I sensitized the cyanotype from the previous session, re-registered the positive, and re-exposed it. The cyanotype blue survives the initial coating but is gone by the end of exposure. Presumably the existing pigment is being donated to the cuprotype, perhaps contributing to density. Washed, toned in 'complex' toner, washed, and finally iron toned. Instead of the listed formula, I concocted something using ferric nitrate, sodium chloride, sodium sulfate, and muriatic acid. The toning effect seems similar.

Top to bottom: original cyanotype; cuprotype overprint, complex toned; previous plus iron toning


The results would have been pretty magnificent had the highlights remained clearer after the reprint & first toner. Mystery fog... perhaps chemical or even just simple overexposure. As with any print 'it looks better in the hand than on the scan'.

The paper is holding up very well so I'll try to see how many processing cycles I can put it through before it's totally wrecked. Fun stuff

 

[nmp]

I sensitized the cyanotype from the previous session, re-registered the positive, and re-exposed it. The cyanotype blue survives the initial coating but is gone by the end of exposure. Presumably the existing pigment is being donated to the cuprotype, perhaps contributing to density. Washed, toned in 'complex' toner, washed, and finally iron toned. Instead of the listed formula, I concocted something using ferric nitrate, sodium chloride, sodium sulfate, and muriatic acid. The toning effect seems similar.

Top to bottom: original cyanotype; cuprotype overprint, complex toned; previous plus iron toning
View attachment 361152

The results would have been pretty magnificent had the highlights remained clearer after the reprint & first toner. Mystery fog... perhaps chemical or even just simple overexposure. As with any print 'it looks better in the hand than on the scan'.

The paper is holding up very well so I'll try to see how many processing cycles I can put it through before it's totally wrecked. Fun stuff

Interesting....

When I did something similar, I didn't see a loss of cyano blue from underneath, so I got green as a combo with un-toned cupro on top and dark warm color with Kferri toning.

Re: Cuprotype Experiments/Observations

groups.io

hmm....requires further investigation. As I understood, copper cannot steal ferrrocyanide from iron but iron can from copper. Hence I did cyano first.

Only thing I can think of is you are bleaching the Prussian blue to Prussian white during re-exposure hence the loss of blue density Perhaps it would come back with peroxide or time/temperature. I don't know if you let sit around or went straight to iron toning.

:Niranjan.

 

[Bronson Dugnutt]

One more round of silver intensification and iron toning. I'll probably seal the print at this point and look into surface treatments. Adding a bit of gloss would be nice.



A first attempt on Strathmore cold press watercolor 500. half-frame 35mm -> 4x5" projected digital negative; complex toner w/ citric acid, iron-toned; auto-corrected scans.

 

[Jan de Jong]

dear All,

As we finally had some sun again, I have some developments where I get some positive instead of negative with help of the Copper Sulfate. Be it probably more a fill in of the underexposed part reversing to stand out.

I have put this print in FeSO4 and then the copper part darkens. I probably should have tried first to bleach to remove the Prussian Blue first. Picture taken where it is still in the washing water.

The print is now drying I will add tomorrow the result.

Some details
FAC+Tartaric+Copper Sulfate as emulsion layer
Short exposure 20 minutes
development with
Ferricyanide+ Tartaric acid - brushed on exposed print
size A4
note: this paper was coated 8 month ago and still working fine


After exposure before development

Anyway, Copper Sulfate with Cyanotype stays interesting.


Regards
Jan.

 

[nmp]

Anyway, Copper Sulfate with Cyanotype stays interesting.

Indeed. Thanks for sharing.

:Niranjan

 

[Jan de Jong]

As said yesterday in the link a scan of the dried print. It did darken quite a bit in the lighter parts, also the white paper yellowed substantially.


Regards
Jan.

 

[shutterbags malone]

I wonder if anyone could help, I'm also struggling with the Cuprotype process. I started out making some last week, and the first batch, following the recipe found here https://www.alternativephotography.com/cuprotype-process/

The first time I mixed the chemistry I was a little haphazard and probably didn't measure exactly, but I didn't take notes. The first prints were done using a salt printing negative and a professional exposure unit. 30 minutes exposure gave a weak, but useable print. 45 minutes exposure gave a good print. It was suggested to me to try double coating, so I added a second coat of chemistry, and these gave reasonable D.Max at 30 minutes, better than the single coated paper.

A few days later I tried to repeat this, I measured chemistry as follows:

5g FAC made up to 10g with water
3g Copper Sulphate made to 30g with water
2g Hypo made to 20g with water

I combined the FAC and CuSO4 and then mixed in the hypo. I applied with a brush and tried both single and double coating paper. After 30 minutes exposure the image was weak, severely lacking highlight details. After 1 hour of exposure I got a print similar to the one I had previously but with better contrast.

Thinking the UV bed or FAC might be playing up I've tested a cyanotype with the same salt negative, after 20 minutes of exposure the shadows had started to reverse. On development the cyanotype looks good, although with thin highlights perhaps from the dense salt negative. A normal Cyanotype negative on this bed takes 12 minutes for maximum black, so considering the negative density this seems ok to me.

I read this entire thread looking for an answer, I've tried making a solution of
5g FAC/3g CuSO4/3g Hypo in both 45ml and 60ml of solution, and with and without Tween 20. The thinner solution with tween was the best, although I think I added too much tween as there were small bubbles on the surface while coating. After 30 minutes of exposure the prints without Tween almost completely washed out, worse than the previous attempts. With 45minutes exposure the tween print was OK, but still very thin, thinner than the previous two printing sessions!

I've noticed the instruction of leaving to dry 5 minutes until the paper looks matt, mine goes matt within 1-2 minutes. I'm using Fabriano Unica which I know should be fine for the process (not pretreating the paper in any way). Negatives are made on an Epson Inkjet with Permajet Digital Negative Film which is the best I've been able to source in the UK and works well for salt prints.

 

[koraks]

Welcome aboard @shutterbags malone ! Fortunately, the author of the article you linked to is a regular poster here, so I imagine he'll be around shortly to offer his insights. @fgorga is always very constructive, helpful and has useful input.

 

[fgorga]

I wonder if anyone could help, I'm also struggling with the Cuprotype process. I started out making some last week, and the first batch, following the recipe found here https://www.alternativephotography.com/cuprotype-process/

The first time I mixed the chemistry I was a little haphazard and probably didn't measure exactly, but I didn't take notes. The first prints were done using a salt printing negative and a professional exposure unit. 30 minutes exposure gave a weak, but useable print. 45 minutes exposure gave a good print. It was suggested to me to try double coating, so I added a second coat of chemistry, and these gave reasonable D.Max at 30 minutes, better than the single coated paper.

Not a good approach to alt process and I am not saying that because I wrote the instructions!!!

Alt process printing has enough variability even if you carefully control the things that are easy to keep constant and precise. Best practice is to work carefully.

A few days later I tried to repeat this, I measured chemistry as follows:

5g FAC made up to 10g with water
3g Copper Sulphate made to 30g with water
2g Hypo made to 20g with water

Did you actually make weight/weight solutions? My instructions call for weigh per volume solutions.

There will be a small difference in the actual concentration of solute using w/w rather than w/v. I haven't a clue if this difference is important.

I combined the FAC and CuSO4 and then mixed in the hypo. I applied with a brush and tried both single and double coating paper. After 30 minutes exposure the image was weak, severely lacking highlight details. After 1 hour of exposure I got a print similar to the one I had previously but with better contrast.

Thinking the UV bed or FAC might be playing up I've tested a cyanotype with the same salt negative, after 20 minutes of exposure the shadows had started to reverse. On development the cyanotype looks good, although with thin highlights perhaps from the dense salt negative. A normal Cyanotype negative on this bed takes 12 minutes for maximum black, so considering the negative density this seems ok to me.

Cuprotype does require long exposures. My exposure unit with 405 nm LEDs takes about 40 min for a cuprotype.

In comparison, I expose 5 min for a cyanotype and 7 min for a salt print or a Pt/Pd print.

Thus, I am guessing that your UV source is a bit less powerful than mine. Therefore, 1 hour is not unreasonable and quite possibly you might need even more exposure (80-90 min?) than that.

The long exposure times are, in my view, the "Achilles heel" of cuprotype.

I read this entire thread looking for an answer, I've tried making a solution of
5g FAC/3g CuSO4/3g Hypo in both 45ml and 60ml of solution, and with and without Tween 20. The thinner solution with tween was the best, although I think I added too much tween as there were small bubbles on the surface while coating. After 30 minutes of exposure the prints without Tween almost completely washed out, worse than the previous attempts. With 45minutes exposure the tween print was OK, but still very thin, thinner than the previous two printing sessions!

Regarding your solutions in this section... the final concentrations are quite far from those I used.

The final concentration of each component (as it goes on the paper) using the solutions I prescribe are 8.3% (w/v) for the FAC, 5% (w/v) for the copper and 3.3% (w/v) for the hypo.

Placing the amounts of solids you specify in 45 mL gives final concentrations of 11%, 6.6% and 6.6% (FAC, Cu, hypo). These are all way off from what I specify.

Using 60 mL, the final concentrations are 8.3%, 5% and 6%. The first two are spot on but the last is almost twice what I use.

I have no idea how critical the concentrations (or the ratios of components) are as I have not tested any others.

However, as I used to stress to students, it is always best to follow a known protocol until you can reproduce the reported result before starting to make changes.

Regarding the Tween 20... how much are you using?

I have never used Tween with cuprotype, but when I do use it for other processes, I use 1 or 2 drops of a 10% (w/v) solution in 1 mL of sensitizer. A little goes a long way.

I've noticed the instruction of leaving to dry 5 minutes until the paper looks matt, mine goes matt within 1-2 minutes. I'm using Fabriano Unica which I know should be fine for the process (not pretreating the paper in any way). Negatives are made on an Epson Inkjet with Permajet Digital Negative Film which is the best I've been able to source in the UK and works well for salt prints.

Regarding drying time... I presume that the instruction you refer to is somewhere in the above thread.

This is not my practice, I dry sensitized paper for a minimum of 1 hour. Sensitized paper is fairly stable so longer is also reasonable. I have exposed paper up to roughly 24 hours after coating without noticing any ill effects, but I have not investigated this systematically.

I have used Unica without pre-treatment for cuprotype so I don't think this is an issue. Cuprotype does not seem too picky about paper.

I use generic OHP film (sold for silk screen).

Hope this helps.

P.S. @koraks... thank you for the kind words!

 

[nmp]

I wonder if anyone could help, I'm also struggling with the Cuprotype process. I started out making some last week, and the first batch, following the recipe found here https://www.alternativephotography.com/cuprotype-process/

The first time I mixed the chemistry I was a little haphazard and probably didn't measure exactly, but I didn't take notes. The first prints were done using a salt printing negative and a professional exposure unit. 30 minutes exposure gave a weak, but useable print. 45 minutes exposure gave a good print. It was suggested to me to try double coating, so I added a second coat of chemistry, and these gave reasonable D.Max at 30 minutes, better than the single coated paper.

A few days later I tried to repeat this, I measured chemistry as follows:

5g FAC made up to 10g with water
3g Copper Sulphate made to 30g with water
2g Hypo made to 20g with water

I combined the FAC and CuSO4 and then mixed in the hypo. I applied with a brush and tried both single and double coating paper. After 30 minutes exposure the image was weak, severely lacking highlight details. After 1 hour of exposure I got a print similar to the one I had previously but with better contrast.

So what is the problem here - longer exposure? Because better contrast is good. You can tweak the negative curve to tackle the higher contrast. Longer exposure as @fgorga mentions is par for the course and each person with their own exposure unit will have different exposure time. Also, I would not do a full print before I have found the proper standard exposure time using a test strip. You would have to do that for every new set of materials/process conditions you try out.

I am also not a fan of double coating (not sure who recommended it) - it's another complication in the process I would rather not try before I have exhausted other means to improve the print.

Another question - are you doing the ferricyanide treatment before judging the print? Because without it, the print is indeed rather light and you would gain density after ferricyanide and even more so after acid-toning, particularly in the highlights - even showing a bit of fog which is absent in the first step.

By the way, I also make my solutions as w/w rather than w/v as I think the former is more accurate if making very small quantities (particularly good for experimentation, which I tend to do indefinitely.) And as long as the same methodology is used for apple to apple comparison, you should be okay.

I read this entire thread looking for an answer, I've tried making a solution of
5g FAC/3g CuSO4/3g Hypo in both 45ml and 60ml of solution, and with and without Tween 20. The thinner solution with tween was the best, although I think I added too much tween as there were small bubbles on the surface while coating. After 30 minutes of exposure the prints without Tween almost completely washed out, worse than the previous attempts. With 45minutes exposure the tween print was OK, but still very thin, thinner than the previous two printing sessions!

This has more thiosulfate than the earlier case. If I remember correctly, that did tend to require slightly longer exposure and the contrast went up as well, so your results are in agreement with my own.

By the way, I had been using the word "sulfonic acid" in the posts in this thread (which is obviously wrong) - it should read "sulfamic acid" the kind you can buy as grout cleaner at the hardware store.

Please share some pictures at various stages so we can estimate how you are doing vs expectations.

Good luck!

:Niranjan.

 

[kiwichris]

I got interested in cyanotype a couple of years ago as an alternative, fairly safe, simple, and affordable way to do something a bit more arty with my photos rather than just have them sit on my PC.
I know a bit about chemistry, and knowing that silver is what is used for traditional photography, wondered if there were any other transition metals that are photosensitive, and that led me to the alternative photography website. Turns out there are a few, but either they're expensive, toxic or both, but cuprotype caught my attention because it's cheap and fairly non-toxic.

The yellow and pink results interested me, as I can't get those so easily with cyanotype - well yellow to an extent, but the other toned results are not so different to what I could achieve with cyanotype.

What really interested me was the possibility of combining processes to get duotone or more in a single image.

Looking at the yellow and pinkish red, of cuprotype untoned or toned with KFeCN and knowing that I can tone cyanotype to get a reasonable black, I wondered if I could make CMYK images.

I've enjoyed experimenting with toned cyanotypes and that extends the range of possibilities, but they're still monochrome. I've hand coloured a few using watercolour pencils or paints, but though lightfast, since they're watercolour, they're not waterproof.

This isn't ink, it's photosensitive chemistry, and I think I read here or on alternative photography that order matters, as cyanotype chemistry applied over cuprotype can convert cuprotype to cyanotype.

Here's an effort made from 3 separations:

Black: Cyanotype toned with instant coffee for about 5 minutes. Gives more of a blue/black than true black, but I found it stains the paper less than other toners.

Blue: Traditional cyanotype

Yellow: Untoned Cuprotype using CuSO4, FAC, Sodium Thiosulfate recipe.

I deliberately brushed the layers on a bit irregularly, as I want more of a painterly look than a 'perfect' reproduction. I have an inkjet for that!

Actually everything is done on a budget. I use an old laser printer someone donated to me, and a sheet of glass out of an old fridge to hold the negative in place during exposure - hence the scratch marks on the image, and some blotches from where the printer drum is getting tired.
I exposed in the sun. Being in the southern hemisphere with clear skies and close to the ozone hole, there's plenty of UV around most of the time.

Second image is CMY (I didn't bother doing a black separation)

I did cyanotype first, then cuprotype and toned it with KFeCN, then finally cuprotype without toning.

I realised subsequently after reading here, I should have washed longer to remove residual unexposed cuprotype chemicals, and I'm not sure whether the CMYK separations in Photoshop are ideal for this and whether there's a better way to produce negatives, but at least I've demonstrated that the principle works.

Also, I suspect the cuprotype emulsion ends up toning the cyanotype, so I'm not sure if there's a way to retain a blue sky.

I was careful to select images where there was clear separation of colours in different parts of the image so they'd be more likely to work.

Image below is a cherry tree in blossom on a grassy hillside, so it actually was pinkish. The top image had dry grass and the structure actually is golden yellow.

Certainly not photorealistic colours, but I still like the aesthetic, and will keep experimenting.

I'd be interested to know if anyone else has tried this kind of process and what sort of success they've had.

 

[koraks]

Welcome aboard @kiwichris!
Your experiments in CMY cuprotype remind me of this: https://www.photrio.com/forum/threads/showcase-for-your-hcwps.199853/post-2801289

 

[kiwichris]

Your experiments in CMY cuprotype remind me of this: https://www.photrio.com/forum/threads/showcase-for-your-hcwps.199853/post-2801289

I haven't attempted a tricolour cyanotype as I haven't found a toner yet that I have access to that could give the magenta, but then I discovered cuprotype, so decided to try with that.
Something that I guess would be interesting to compare is doing the yellow with untoned cuprotype vs bleached cyanotype.

 

[nmp]

I got interested in cyanotype a couple of years ago as an alternative, fairly safe, simple, and affordable way to do something a bit more arty with my photos rather than just have them sit on my PC.
I know a bit about chemistry, and knowing that silver is what is used for traditional photography, wondered if there were any other transition metals that are photosensitive, and that led me to the alternative photography website. Turns out there are a few, but either they're expensive, toxic or both, but cuprotype caught my attention because it's cheap and fairly non-toxic.

The yellow and pink results interested me, as I can't get those so easily with cyanotype - well yellow to an extent, but the other toned results are not so different to what I could achieve with cyanotype.

What really interested me was the possibility of combining processes to get duotone or more in a single image.

Looking at the yellow and pinkish red, of cuprotype untoned or toned with KFeCN and knowing that I can tone cyanotype to get a reasonable black, I wondered if I could make CMYK images.

I've enjoyed experimenting with toned cyanotypes and that extends the range of possibilities, but they're still monochrome. I've hand coloured a few using watercolour pencils or paints, but though lightfast, since they're watercolour, they're not waterproof.

This isn't ink, it's photosensitive chemistry, and I think I read here or on alternative photography that order matters, as cyanotype chemistry applied over cuprotype can convert cuprotype to cyanotype.

Here's an effort made from 3 separations:

Black: Cyanotype toned with instant coffee for about 5 minutes. Gives more of a blue/black than true black, but I found it stains the paper less than other toners.

Blue: Traditional cyanotype

Yellow: Untoned Cuprotype using CuSO4, FAC, Sodium Thiosulfate recipe.

I deliberately brushed the layers on a bit irregularly, as I want more of a painterly look than a 'perfect' reproduction. I have an inkjet for that!

Actually everything is done on a budget. I use an old laser printer someone donated to me, and a sheet of glass out of an old fridge to hold the negative in place during exposure - hence the scratch marks on the image, and some blotches from where the printer drum is getting tired.
I exposed in the sun. Being in the southern hemisphere with clear skies and close to the ozone hole, there's plenty of UV around most of the time.

View attachment 382330

Second image is CMY (I didn't bother doing a black separation)

I did cyanotype first, then cuprotype and toned it with KFeCN, then finally cuprotype without toning.

I realised subsequently after reading here, I should have washed longer to remove residual unexposed cuprotype chemicals, and I'm not sure whether the CMYK separations in Photoshop are ideal for this and whether there's a better way to produce negatives, but at least I've demonstrated that the principle works.

Also, I suspect the cuprotype emulsion ends up toning the cyanotype, so I'm not sure if there's a way to retain a blue sky.

I was careful to select images where there was clear separation of colours in different parts of the image so they'd be more likely to work.

Image below is a cherry tree in blossom on a grassy hillside, so it actually was pinkish. The top image had dry grass and the structure actually is golden yellow.

Certainly not photorealistic colours, but I still like the aesthetic, and will keep experimenting.

I'd be interested to know if anyone else has tried this kind of process and what sort of success they've had.

View attachment 382333

Interesting work. Thanks for sharing. Only cyano/cupro mix I did was shared here:

Re: Cuprotype Experiments/Observations

groups.io

:Niranjan.

 

[Jan de Jong]

Just a test to see if I could combine the Cyanotype and Cuprotype, I did a while ago.
Size A5
Paper Clarefontain 250gr aquarell

I have started with the Cyanotype, normal mix of 2:1 FAC + KFerri and 10ml of dest water
Exposure 20 mins of UV light Top row and developed is pict nr 4. and dry

then add the layer with the Cuprotype mix based on the Hypo formula
2:1:0.5 FAC + Coppersulfate + Hypo in 10ml of dest water.
I weight the chemicals and add all together then add the water and put in the sonic bath to quickly mix a small batch of emulsion.

Adding this on top of the Cyanotype. I noticed it bleaches the cyanotype. (pic 5)
expose in UV light for 40 mins (double the cyanotype, just a guess)

Develop by first rinsing in tap-water picture 8

Then put in a bath of 1:1:1 KFerri + Kferro + Tartaric acid . I used 3gr of each + 150ml of dest water.

This brings suddenly back the Blue and brown-orange color. It looked amazing when wet. When dried it looks like picture nr 9. More muted but very intense colors.
I was surprised about the whites, they seem not to get any of the staining from the coppersulfate with this.

I have tried to do this with some printed negatives but it needs a good density.

cheers Jan.