lifespan of Tannic acid in solution?

I just mixed up some tanic acid toner and I was wondering if I could keep it for use at a later time.

I mixed up the toner as:
25grams of tanic acid to 200ml of water

Great results so far, i'm bleaching with borax 35 grams to 500 ml, 15 min wash, tanic acid till color is achived. Instead of browns, im getting warm blacks. They look fantastic I'll share some examples when their dry

Is this for cyanotype? Traditional or Type II? Are you bleaching completely or only partially?

I'm looking forward toward trying this in a month or so when I get some time. Looking forward to you sharing some images...

--Greg

Yup, this is for traditional. And I just got surprised as all heck when a batch on a different paper turned a GORGEOUS purple/brown. I'm getting some surface stain, so I lose my perfect whites, but the rest of the tonality is preserved. In fact, the shadows are now deeper than they were before, so it could be argued that im expanding the contrast. Next time I mix up tanic acid, i'm going to halve the strength and see if I can control the toning better. Pics will be posted tomorrow

I'm going to throw my solution into a bottle and we'll see if it keeps a week

Alex, use hard papers with surface sizing to minimize stain, plus, use a more dilute toner; 25g in 200ml water is pretty strong - I was mixing my tannic acid toner by putting 1 dessert spoon into 1000ml only! You don't need to see the result "in the toner", 5 to 10 minutes toning is plenty enough; the print will darken considerably while drying. You'll experience less stain if you keep your toning times as short as possible.

Also, it's crucial to process well the paper before toning. You have to clear iron from the whites completely; do normal development then use a citric acid or Na2.EDTA or Na4.EDTA + citric acid (target pH 3-4) clearing bath to eliminate all iron from your paper to protect the whites. If not, you'll get extra stained highlights. (In every parts of the paper where the sensitizer was applied - actually...)

The toner solution keeps for months IME, I was occasionally filtering it to clear debris and such.

BTW, tannic acid / tannin toning works well with both Trad. Cyanotype and New Cyanotype.

Hope this helps,
Loris.

See one of my best examples below:


Regards,
Loris.

Loris Medici said:

See one of my best examples below:

Regards,
Loris.

Click to expand...

Gorgeous split tone print Loris! Definitely got to try out Cyanotype and toning once...

Loris Medici said:

See one of my best examples below:

Cappadocia
(Split toned new cyanotype)​

Regards,
Loris.

Click to expand...

If you could only hear how many times I just said 'hmm' and 'ahh'

So much was answered I thought the tanic acid was strong, but thats what was recommended in christopher james book. I will make a note to try that with a lighter dilution. I experienced surface stain where there was no cyanotype chemistry- definitely due to the high concentration of tannic acid. I'll be sure to add the citric acid when coating more absorbent material like the canson paper.

PS. everyone needs to try coating on the epson premium luster paper. Its so easy, perfect color, gorgeous luster, and its basically plastic so washing is easy, it cant fall appart.

alexhill said:

So much was answered

Click to expand...

You may find this recent thread I started interesting as well:

Chemistry of tea-toning cyanotypes:
(there was a url link here which no longer exists)

Marco

That Epson Premium luster suggestion is very interesting Alex. Will try that -> it gives very good dmax compared to Canson. (Perhaps due to less surface scattering...) Could be a nice suggestion for workshop participants...

Regards,
Loris.

I make up tannic acid analytical standard solutions at 1000 parts per million and they certainly last a year. You should have no problems from the stability of tannic acid.

I was surprised how well it worked. Its incredible and looks great. I've also used a hahnemuhle digital baryta, which got a pleasing crackled surface, I'll post a photograph of that in a little bit. Right now I've got to go bury electrical conduit

alexhill said:

I was surprised how well it worked. Its incredible and looks great. I've also used a hahnemuhle digital baryta, which got a pleasing crackled surface, I'll post a photograph of that in a little bit. Right now I've got to go bury electrical conduit

Click to expand...

When you say "pleasing crackled surface", do you mean like reticulation, or "crackle" paint, where the surface coating of the paper is actually cracking? Or is it just an inherent surface quality of the paper?

--Greg