Tannic Acid Toning a Cyanotype

[Andrew O'Neill]

Popped together a video showing the toning of the print, Columns, being bleached and redeveloped in Tannic Acid. It's such a simple process...easier than shooting/editing videos! Both the untoned and toned print are in the Gallery. I hope you like it!

 

[koraks]

I saw the print; really like the toned version, more so than the untoned one. The highlights differentiate a lot better in the toned version, which your image really benefits from.

I should have some tannic acid on order; some years ago I used to bleach cyanotypes in household bleach or carbonate and then tone with tea. I also once made an extract of oak that gave a very nice purple tone. It was a specific type of American oak that gave this color; one with particularly small fruits. European oak didn't have the same effect and toned more brown.

Pretty much everything you throw at a cyanotype stains like a motherf*** except pure tannic acid it seems, which is why I'd like to give it a try sometime.

 

[Andrew O'Neill]

I saw the print; really like the toned version, more so than the untoned one. The highlights differentiate a lot better in the toned version, which your image really benefits from.

I should have some tannic acid on order; some years ago I used to bleach cyanotypes in household bleach or carbonate and then tone with tea. I also once made an extract of oak that gave a very nice purple tone. It was a specific type of American oak that gave this color; one with particularly small fruits. European oak didn't have the same effect and toned more brown.

Pretty much everything you throw at a cyanotype stains like a motherf*** except pure tannic acid it seems, which is why I'd like to give it a try sometime.

How did you like the tea tone? Does it stain the highlights?

 

[koraks]

I quite liked the tone; it's sort of a cool brown, if that makes sense. It doesn't have any of the magenta hues other toners have, and leans distinctly towards cyan.
Yeah, sadly it stained the paper really badly. The type of tea will make some difference, but they all stain in the end as far as I can tell.

 

[nmp]

I quite liked the tone; it's sort of a cool brown, if that makes sense. It doesn't have any of the magenta hues other toners have, and leans distinctly towards cyan.
Yeah, sadly it stained the paper really badly. The type of tea will make some difference, but they all stain in the end as far as I can tell.

Highlight staining and indeed of the paper itself is the Achilles heel of cyanotype toning - and tea is not one of better ones in that department. If you look at the chemistry, it is not at all surprising since tannic acid / tannins / polyphenols attach to cotton/cellulose via hydrogen bonding - something that makes them good mordants in dyeing industry which is a pretty ancient practice (the word tanning comes from that.)

:Niranjan.

 

[koraks]

I learn something new every day from you Niranjan. Stick around!

 

[glbeas]

Does the tannic acid toning enhance the permanence of the image?

 

[Mainecoonmaniac]

Popped together a video showing the toning of the print, Columns, being bleached and redeveloped in Tannic Acid. It's such a simple process...easier than shooting/editing videos! Both the untoned and toned print are in the Gallery. I hope you like it!

Nice! thanks for sharing. Cyanotypes are fun to make. I got tired of the Prussian blue so I stopped making them. I'll revisit making cyanotype and tone them. I don't know if I missed it, but can you reuse the tannic acid or toss it after each toning session?

 

[FotoD]

Does the tannic acid toning enhance the permanence of the image?

The untoned and the toned cyanotype are both very permanent. Sorry, but I can't quantify it more than that. "Cyanomicon" by Mike Ware contains a lot of knowledge, also about archival aspects.

 

[Andrew O'Neill]

Nice! thanks for sharing. Cyanotypes are fun to make. I got tired of the Prussian blue so I stopped making them. I'll revisit making cyanotype and tone them. I don't know if I missed it, but can you reuse the tannic acid or toss it after each toning session?

Thankfully you can reuse it. Tannic Acid is not cheap. I paid $13 Canadian plus taxes for only 100g, and they was pre-covid.

 

[Patrick Robert James]

Nice print Andrew!

I've always toned with tea with the downside being the paper gets stained too. I don't mind that though. The tones you got look mighty tasty though. I might have to try that.

 

[nmp]

I learn something new every day from you Niranjan. Stick around!

Thanks. It works both ways.

:Niranjan.

 

[fgorga]

Does the tannic acid toning enhance the permanence of the image?

Not in my experience.

Here is a quick snap (from this afternoon) of a cyanotype triptych that has been hanging on my wall (out of direct sun) for roughly nine years. The prints were made and framed in 2006. They were displayed in a couple of exhibitions and then stored until I hug them in our house (as I said nine years ago).

The left print is an untoned cyanotype. The middle print was bleached with ammonia and toned with tannic acid. The right print was bleached with sodium carbonate and toned with tannic acid.

For comparison, here are scans (composited into a single file) of the exact same prints shortly after they were made:

I'll let you draw your own conclusions.

It is well known that cyanotypes under glass do fade with time (see Mike Ware's Cyanomicron book) and that they can be restored upon re-exposure to open air in the dark. I have not tried this with these prints, but know that the frame is off the wall, I may try this.

Regards,

--- Frank (www.frg-photo.com --- www.gorga.org/blog)

 

[fgorga]

Thankfully you can reuse it. Tannic Acid is not cheap. I paid $13 Canadian plus taxes for only 100g, and they was pre-covid.

It is possibly worth noting that tannic acid is a specific compound and can be purchased in more-or-less pure form. It should not be confused with 'tannins".

Tannins can be purchased fairly cheaply... certainly more cheaply than one can buy tannic acid. Tannins, a complex mixture of polyphenols one of which is tannic acid.

I have used tannic acid successfully for toning cyanotypes much as Andrew describes. It works nicely without staining the paper.

Tannins do not work well for toning cyanotypes as they cause significant staining of the paper with a concomitant loss of contrast similar to what one sees when toning with tea, coffee or wine. This similarity is not surprising, as these beverages all contain complex mixtures of polyphenols of which tannic acid is a small fraction.

Regards,


--- Frank (www.frg-photo.com --- www.gorga.org/blog)

 

[fgorga]

Thankfully you can reuse it. Tannic Acid is not cheap. I paid $13 Canadian plus taxes for only 100g, and they was pre-covid.

Solutions of tannic acid are likely to grow mold upon storage.

I would image than one could try adding small amounts of thymol to a tannic acid solution to inhibit this growth, much has some folks do with their ferric ammonium citrate solutions. (I have not tried this but I don't see why it shouldn't work.)

Storing the tannic acid solution in the refrigerator would also slow the growth of mold.

Regards,


--- Frank (www.frg-photo.com --- www.gorga.org/blog)

 

[Andrew O'Neill]

Solutions of tannic acid are likely to grow mold upon storage.

I would image than one could try adding small amounts of thymol to a tannic acid solution to inhibit this growth, much has some folks do with their ferric ammonium citrate solutions. (I have not tried this but I don't see why it shouldn't work.)

Storing the tannic acid solution in the refrigerator would also slow the growth of mold.

Regards,


--- Frank (www.frg-photo.com --- www.gorga.org/blog)

I wondered about that. I wonder if one could put a wee bit of dichromate in...

 

[fgorga]

I wondered about that. I wonder if one could put a wee bit of dichromate in...

That would, in my estimation, also work.

 

[Mainecoonmaniac]

Thankfully you can reuse it. Tannic Acid is not cheap. I paid $13 Canadian plus taxes for only 100g, and they was pre-covid.

Thanks for the tip! I’m going to try your toning method. I hope tannic acid won’t go moldy if it’s stored for a bit.

 

[grahamp]

I have only done this with wine tannin, and yes, the solution will go moldy. I have had some nice results on commercial Sunprint paper (see Wine tannin toned cyanotype in Gallery ) and I will probably do it again.

I like the result you obtained - a little like platinum with the soft greys.

 

[Vaughn]

Bostick and Sullivan have tannic acid at $87 US for a kilo (and $46 for 1.1 pound). Artcraft for $43 a pound.

Plus shipping and taxes, of course. A little cheaper than most prices on Amazon...might find a better deal, but I prefer to support B&S.

 

[Andrew O'Neill]

I'm wondering if a wee bit of dichromate might keep mold in check?

 

[Andrew O'Neill]

I have only done this with wine tannin, and yes, the solution will go moldy. I have had some nice results on commercial Sunprint paper (see Wine tannin toned cyanotype in Gallery ) and I will probably do it again.

I like the result you obtained - a little like platinum with the soft greys.

Nice result! I'll have to try some wine tannin. Thanks!

 

[Andrew O'Neill]

Bostick and Sullivan have tannic acid at $87 US for a kilo (and $46 for 1.1 pound). Artcraft for $43 a pound.

Plus shipping and taxes, of course. A little cheaper than most prices on Amazon...might find a better deal, but I prefer to support B&S.

Looks like I can get 454g (1lb) from Argentix up here for $39.99. That's $30 in your money. Just found some wine tannin on amazon dot ca. $30 Cdn for 454g.

 

[fgorga]

I'm wondering if a wee bit of dichromate might keep mold in check?

see post #17 in this thread.

 

[fgorga]

Nice result! I'll have to try some wine tannin. Thanks!

Wine tannins are likely to stain the paper.

See my explanation of the difference between tanniic acid and tannins in post #14 above.

Since tannins are a complex mixture whose composition is not really controlled, one may be able to find a product from a specific supplier or even a specific batch from a single supplier that works for toning without staining. But I would not necessarily expect things to work the same when I purchased a new batch.

Of course, to some the unpredictability of alt processes is part of the charm!