Cyanotype blues

[Larry Bullis]

These suggestions are great. I suspect that the CA treatment enables the paper to retain the pigment better, without its washing out. I get great blacks, but the time in the wash is critical; not enough, get discoloration, and too much, image degrades.

 

[mooseontheloose]

Just a small update. I've tried a new paper (Arches Platine), a wetter brush, and less cyanotype solution. The brush strokes have definitely improved (no beading whatsoever), and I can see an overall improvement in the coating as well. However, I have yet to see the final results as I haven't had a chance to get out in the sun yet.

Lukas and Dave -- if I can get a hold of citric acid I'd like to try that as well, however, at the moment I'm working on one improvement at a time. Thanks for the suggestions though!

 

[Lukas Werth]

I use 40g per litre of citric acid for the first wash(around 1-3 mins) ... attached is an example showing the difference between using a citric acid for the first bath and not using one. CA on the right.

Yes, according to my experience citric acid is the best organic acid for cyanotypes. Depending on the paper base, it might stain or yellow the highlights somewhat, but it gives deeper blues than acetic acid which is often recommended - and easily available as vinegar. To some extend, of course, this remains a matter of taste, of how you would like your pictures to look.

Dave, you refer to Cyanotype II - is this New Cyanotype or just traditional cyanotype with citric? If it is New C., then I think you should, with hydrochloric or nitric acid for the first wash (see Mike Ware's website), get much deeper blues still, the border being very nearly black.

Bowzart, i.m.e. the image degradation during the wash is (of course) due to slightly alkaline, or hard water. Here acetic acid/vinegar comes handy: you may just add some to the dish every few minutes (depending on your water flow) in order to stabilize the image. The colour will be more cyan, though, which you might like to adjust with a short wash with plain water in the end, with a short dip in a week dichromate solution, or with a weak solution with a weak alkali (I use sodium sulfite) near the end - the latter has to be exercised carefully, it gives you purplish highlights (and clears them) which you might or might not find attractive (I do).

 

[Lukas Werth]

I forgot to mention that what you technically start with sodium sulfite is of course a bleaching process, as you would for toning.
And, as I have said before, I would not use Arches Platine either. The paper looks beautiful, but Arches keeps tinkering with its formula. Over the years, I have run into unexpected differences and bad batches again and again, and this may be quite frustrating.

 

[Akki14]

Just a small update. I've tried a new paper (Arches Platine), a wetter brush, and less cyanotype solution. The brush strokes have definitely improved (no beading whatsoever), and I can see an overall improvement in the coating as well. However, I have yet to see the final results as I haven't had a chance to get out in the sun yet.

Lukas and Dave -- if I can get a hold of citric acid I'd like to try that as well, however, at the moment I'm working on one improvement at a time. Thanks for the suggestions though!

Do a 50/50 soak tray of vinegar and tap water if you can't be bothered to get the citric acid. Though I've found for me that makes the blue come off really bad and go everywhere and stain the paper but I'm weird :rolleyes:

 

[Vaughn]

I forgot to mention that what you technically start with sodium sulfite is of course a bleaching process, as you would for toning.
And, as I have said before, I would not use Arches Platine either. The paper looks beautiful, but Arches keeps tinkering with its formula. Over the years, I have run into unexpected differences and bad batches again and again, and this may be quite frustrating.

My understanding (which could be wrong) is that the sizing used in the paper is changed seasonally due to the temperature at the factory. Appearently, some sizing material is easier to use in the process of making the paper at low temps and some at high temps. Since the different sizing does not affect the use of the paper for its intended purpose (watercolor painting), they don't worry about it.

The Bergger COT320 is made by Arches to a specific formula...thus in theory, should be more consistant. But only in theory, I'm afraid. I have a "bad" batch of COT320 in 16x20.

Vaughn

 

[Lukas Werth]

My understanding (which could be wrong) is that the sizing used in the paper is changed seasonally due to the temperature at the factory. Appearently, some sizing material is easier to use in the process of making the paper at low temps and some at high temps. Since the different sizing does not affect the use of the paper for its intended purpose (watercolor painting), they don't worry about it.

The Bergger COT320 is made by Arches to a specific formula...thus in theory, should be more consistant. But only in theory, I'm afraid. I have a "bad" batch of COT320 in 16x20.

Vaughn

I have never heard about this seasonal change of the sizing.
Arches platine is, however, for all I know not marketed primarily as a water colour paper, but, as the name indicates, for *alternativeprocesses*, foremost, of course, platinum prints. Now pt/pd is a rather easy process, but I have hade difficulties with some batches making pt/pd prints also. I once or twice got my money refunded, but not the hassle. Good batches generally work normally with pt/pd or kallitypes, though. New cyanotypes are more fickle, and here Arches Platine drove me crazy by once working and once not, until I discovered the citric acid precoating method. Chrysotypes also are less easily made on this paper than one might think; as often as not I ended up with some undesirable pattern of patches which only became visible when the paper was dry.

This Bergger paper is apparently a baryta paper without baryta coating, but cut to photographic sizes. This alone makes it uninteresting for me. I want to print on watercolour for the haptics and the subtle paper tones (I certainly don't need this pure, brilliant white), and tear the paper to sizes I want.