Paper white in cyanotypes

[jaspergoodall]

Hi All, hopefully someone here will know something about my question:
I have been trying out cyanotype using QTR and Quadtone Profiler DN - seem to have landed on an ink blocking density of K35 and have linearised a profile. I made a special blocking density file with no black lines between my grey patches and covered one edge with black paper so I could see as well as possible when I was getting 'paper white'. HOWEVER - many times, when I make a print it seems I cannot get a true paper white - no matter how long I wash the print there is still some cyanotype toning in the highlights outside of the print.
I have been printing with a large black border on the neg so as to mask off and get a clean image border but it seems like the UV is getting through. I can tell because I am not coating the whole paper - leaving areas uncoated as a paper white reference. My question is this - would you expect cyanotype solution to wash totally away if unexposed or is there always going to be some left in the paper (I'm using HPR). I cant work out if somehow the neg is not blocking light and I'm getting exposure 'fogging' or if its just always gonna have a little residual solution left no matter what (which really shows up when I tone the prints). I'm considering trying a much higher ink density like K50 just to see if I can get a white border.
I'm not leaving the paper for ages before exposure, it's drying in a dark room, my solution is made with distilled water.... should it be washing totally clean out?

Thanks for any tips/thoughts.
Jasper

 

[gbroadbridge]

You should get clear white.

Which paper are you using? Paper is usually the problem.

 

[fgorga]

Reading between the lines of the original post, I am guessing that the problem @jaspergoodall is having is a light blue 'stain' (due to small amounts of Prussian blue being made under the black boarder of the negative) and not a yellow stain due residual sensitizer (iron) in the paper after washing. These are two different problems.

A light blue stain means that your negative is not as dense as you imagine and since it is Prussian Blue, it is not likely to be able to be washed out. The simplest solution to this problem is to modestly reduce your exposure time and see if you can still get a satisfactory image while eliminating the stain.

Otherwise you can go back to your process for making negatives and add some more density.

Alternately, you can use rubylith for masking instead of a printed mask. This red film is the traditional material for masking UV sensitive processes. Alas, it is hard to find in small quantities and expensive.

Lastly, one could try adding a red construction paper mask over the printed mask to add density. I have experimented with inexpensive red construction paper as a masking material. It is not as dense in the UV as rubylith and is a bit thicker as well (and thus one might loose a small amount of sharpness). However it is inexpensive and readily available.

I find that using a single sheet of red paper alone with cyanotype gives a very small amount of blue under it, similar to what I think you are seeing. Often it is not really noticable in a native cyanotype but, alas, it becomes very noticeable if one makes toned cyanotypes.

I have not tried it, but I imagine that the additive effect of your printed mask plus a red paper mask might be worth exploring.

If you are having problems with residual sensitizer (i.e. a yellow, or maybe greenish stain), you can try adding small amounts of acid (acetic or citric, are commonly used) to the initial wash water. If your water is too basic you run the risk of converting some of the residual iron to iron hydroxide which is very hard to wash out of the paper.

Alternately (or in addition to acidic washes) you could, as suggested above, try a different paper. My guess is that a different paper would not help with first issue (i.e. the blue stain) but it might be worth a try anyway. Hoowever, it might help with the second issue (i.e. a yellow stain).

Two nice but inexpensive papers I like for cyanotype are Fabriano Unica and Hahn. Bamboo Mixed Media.

Regards,

 

[jaspergoodall]

You should get clear white.

Which paper are you using? Paper is usually the problem.

Hahn’ platinum rag which I assumed was kinda pretty good given that 99% of people seem to recommend for alt process.

 

[jaspergoodall]

Reading between the lines of the original post, I am guessing that the problem @jaspergoodall is having is a light blue 'stain' (due to small amounts of Prussian blue being made under the black boarder of the negative) and not a yellow stain due residual sensitizer (iron) in the paper after washing. These are two different problems.

A light blue stain means that your negative is not as dense as you imagine and since it is Prussian Blue, it is not likely to be able to be washed out. The simplest solution to this problem is to modestly reduce your exposure time and see if you can still get a satisfactory image while eliminating the stain.

Otherwise you can go back to your process for making negatives and add some more density.

Alternately, you can use rubylith for masking instead of a printed mask. This red film is the traditional material for masking UV sensitive processes. Alas, it is hard to find in small quantities and expensive.

Lastly, one could try adding a red construction paper mask over the printed mask to add density. I have experimented with inexpensive red construction paper as a masking material. It is not as dense in the UV as rubylith and is a bit thicker as well (and thus one might loose a small amount of sharpness). However it is inexpensive and readily available.

I find that using a single sheet of red paper alone with cyanotype gives a very small amount of blue under it, similar to what I think you are seeing. Often it is not really noticable in a native cyanotype but, alas, it becomes very noticeable if one makes toned cyanotypes.

I have not tried it, but I imagine that the additive effect of your printed mask plus a red paper mask might be worth exploring.

If you are having problems with residual sensitizer (i.e. a yellow, or maybe greenish stain), you can try adding small amounts of acid (acetic or citric, are commonly used) to the initial wash water. If your water is too basic you run the risk of converting some of the residual iron to iron hydroxide which is very hard to wash out of the paper.

Alternately (or in addition to acidic washes) you could, as suggested above, try a different paper. My guess is that a different paper would not help with first issue (i.e. the blue stain) but it might be worth a try anyway. Hoowever, it might help with the second issue (i.e. a yellow stain).

Two nice but inexpensive papers I like for cyanotype are Fabriano Unica and Hahn. Bamboo Mixed Media.

Regards,

Great reply - you have understood my dilemma perfectly. It’s very light blue residual solution that really stains bad when toning. I will try some red paper. Rubylith seems next to impossible to obtain in the U.K. and what’s available is crazy expensive for what it is. Also I noticed that using less solution when coating helps - obviously there’s less solution to wash out. Have been using a cap full of spirit vinegar, might try more as my water is pretty hard given that it comes out of a chalk aquifer. Have ordered Hahn’ Bamboo - I think I read a post by you that suggested it stains less when toning which sounds like a very good thing. I think a combo of thicker neg, a touch less exposure, more masking, and more vinegar and hopefully I can get better results. My main question I think has been answered - I ought to be clearing all supposedly unexposed cyanotype out if the paper.

 

[gbroadbridge]

Hahn’ platinum rag which I assumed was kinda pretty good given that 99% of people seem to recommend for alt process.

HPR is, in my experience, really bad for cyanotype.
It's good for its intended purpose, like pt/pd.

Try something like Canson XL and I'll bet your problem goes away.

 

[jaspergoodall]

This morning I noticed a blocking density test that made about three days ago, it had another sheet of paper lying on top of it, which, when removed, left a white patch where other areas of ‘paper white’ had subsequently turned blue when left out in the light. This area had had a sheet of black paper over it when I made the exposure, so I can only conclude that HPR is actually really bad at clearing cyanotype chemistry. When I washed it it looked pristine white, evidently I needed a much longer wash time. This was maybe my bad, but I’m certainly going to try different papers, hopefully they clear a bit better and maybe stain less when toning.

 

[PGum]

Jasper,

Tannins are ultra-sensitive to even trace residual iron, producing visible iron tannate. While one iron source comes from trace prussian blue, the other is a result of simply applying sensitizer to the paper. The paper: cellulose, sizing…is happy to bind with the iron. This degree of attraction seems to be paper-dependent. Your hard water makes this worse, as it may have a pH above 7, hydrolyze the ferrric ammonium citrate to some degree on development and has other minerals that may assist in fixing iron.

The best way to mitigate is to develop in water that has been acidified with a small amount of citric acid ( better chelating than acetic), then after drying, post-clear by bathing your paper in a 1% citric acid solution or other ph-neutral or acidic chelator maybe 5-10 mins, then a good long rinse to remove that.

HPR will clear much better in an acidic bath too, in my experience. I have used HPR many times in making cyanotypes and with follow-up tannin-based toning - all good!

 

[Nicholas Lindan]

Rubylith seems next to impossible to obtain in the U.K. and what’s available is crazy expensive for what it is.

Rubylith is a niche product used by the (now defunct) pre-press graphic arts industry. The red layer can be cut through easily and then peeled back from the clear substrate. It was used for masking negatives when making printing plates. Back before computers took over Rubylith was common and not that outrageously priced.

Theatrical lighting gels work just as well for a small fraction of the price. The #25 gel is equivalent to a #25 wratten camera filter.

 

[koraks]

Rubylith seems next to impossible to obtain in the U.K. and what’s available is crazy expensive for what it is.

Theatrical lighting gels work just as well for a small fraction of the price. The #25 gel is equivalent to a #25 wratten camera filter.

Or just use some tin foil from a 1.50 roll bought at Tesco's. It tears of course, but glued to a support (a thin sheet of plastic, Yupo etc.) it'll be sturdy.

 

[jaspergoodall]

Jasper,

Tannins are ultra-sensitive to even trace residual iron, producing visible iron tannate. While one iron source comes from trace prussian blue, the other is a result of simply applying sensitizer to the paper. The paper: cellulose, sizing…is happy to bind with the iron. This degree of attraction seems to be paper-dependent. Your hard water makes this worse, as it may have a pH above 7, hydrolyze the ferrric ammonium citrate to some degree on development and has other minerals that may assist in fixing iron.

The best way to mitigate is to develop in water that has been acidified with a small amount of citric acid ( better chelating than acetic), then after drying, post-clear by bathing your paper in a 1% citric acid solution or other ph-neutral or acidic chelator maybe 5-10 mins, then a good long rinse to remove that.

HPR will clear much better in an acidic bath too, in my experience. I have used HPR many times in making cyanotypes and with follow-up tannin-based toning - all good!

Perfect, thank you! I have just recently started to neutralise my water with acetic, (too much of it and I got quite blue highlights) but I’ll get myself some citric acid. I’m going to experiment with Christina Andersen’s suggestion of a 10%|10% sensitiser, less FAC will hopefully help some way with this too. Cheers

 

[jeffwiedner]

@jaspergoodall - FWIW, to stop staining on cyanotypes on HPR paper, my workflow is 40ml distilled white vinegar per liter of water in two separate baths. The first for no more than 2 mins [more frequently ~1:30] and then the remainder of 5 mins in the second bath. If I'm making a lot of prints, I can use the second bath for the first bath on the subsequent print to save a little chemistry. And to clear the edges, adding a color blocker was the most effective for me. You can find the best color block for your process by going through Peter Mrhar's Easy Digital Negatives process.

Good luck with wrangling this. I understand how frustrating that is when you're feeling confident that you're doing everything right.

 

[Andrew O'Neill]

Never had an issue with HPR and Cyanotypes. But I dropped that paper due to cost...and shipping damage. I have been working on Canson XL Watercolour, from a local art store. Heaps cheaper, and works beautifully.
Check your tap water. Mine tends to lean toward the alkaline. A bit of vinegar in the clearing baths can help prevent staining.

 

[jaspergoodall]

@jaspergoodall - FWIW, to stop staining on cyanotypes on HPR paper, my workflow is 40ml distilled white vinegar per liter of water in two separate baths. The first for no more than 2 mins [more frequently ~1:30] and then the remainder of 5 mins in the second bath. If I'm making a lot of prints, I can use the second bath for the first bath on the subsequent print to save a little chemistry. And to clear the edges, adding a color blocker was the most effective for me. You can find the best color block for your process by going through Peter Mrhar's Easy Digital Negatives process.

Good luck with wrangling this. I understand how frustrating that is when you're feeling confident that you're doing everything right.

Can I ask what dilutions of solution you are using (assuming classic cyanotype)? Previously I was just following Jaquard’s instructions on their tubs of chemistry but have realised it gives a very strong FAC solution which is over 20%. Quite possibly one of the contributing factors to staining.
I mixed up some 10% and am trying 10/10 PFC/FAC now. This gives a slightly lighter DMax - have to see how they look after toning. Might try 15% FAC.

 

[jaspergoodall]

Never had an issue with HPR and Cyanotypes. But I dropped that paper due to cost...and shipping damage. I have been working on Canson XL Watercolour, from a local art store. Heaps cheaper, and works beautifully.
Check your tap water. Mine tends to lean toward the alkaline. A bit of vinegar in the clearing baths can help prevent staining.

Have you ever toned the Canson? Just wondering because I tried Arches Aquarelle HP and it soaked up botanical toning so badly that I rejected it outright because it went very stained. At least HPR stays relatively clean where there has been no sensitiser applied. Be interesting to know how Canson copes.

 

[jeffwiedner]

Can I ask what dilutions of solution you are using (assuming classic cyanotype)?

I use FAC: 20 PF: 10. It has been difficult to get green FAC so I now use brown with oxalic acid. Oxalic has helped improve my exposure time, reduce fogging and help clear highlights. I didn't have success using Jacquard chemistry. So I purchase mine at Bostick and Sullivan. If that's what you have, you might want to consider reducing the percentage of FAC. From what I've read on Christina Z Anderson's testing, the higher FAC creates more bleeding, higher staining and higher potential for fogging. She has a great book on cyanotype, if that's something you want to dig into.

 

[NedL]

A few months ago I ran out of FAC and ordered some Jacquard from amazon. It presumably had ferrous in it and turned blue when mixed with PF. Adding a little H2O2 solved this temporarily but then it needed more and then more again... I returned it. Then I bought a couple bottles from photographer's formulary, and they looked similar and needed H2O2 to work and not precipitate prussian blue. I think there has been a change in suppliers and most of it comes from China now. The formulary stuff still works and I didn't need to add more H2O2 to keep it working... but I think there could be general problems with green FAC these days. This problem could result in light blue staining in unexposed areas of the print.