Cyanotype - crystal like artefacts

[domenan]

Hello,

I have a recurring issue with crystal like artefacts appearing after exposing the paper.
Some time the artefacts cover the whole paper or other time just a specific area or don't appear at all.

I'm currently using Mike Ware solution on Canson Montval watercolour paper.
I use a single coat. I let the coated paper sit for 15 min to dry and then I add a fan to blow room temperature air for about 20 min.
Previously I used hot air but I heard that overheating the solution might cause snow flakes like artefacts which looks very similar to my problem, but I noticed no difference (see page 57 for snow flakes or crystallisation https://manualzz.com/doc/29906433/how-to-make-glass-cyanotypes).

I attached a photo of 2 recent prints. The first photo is showing the problem mainly on the right side and along the borders.
The second photo is completely covered.

I hope anybody can help me.

 

[osella]

Is the paper buffered? Cyanotypes are sensitive to alkaline environments and it looks like there could be some local(or all over) bleaching. If you are set on that paper you may need to acidify the paper to get better results.

I believe Mike Ware’s new cyanotype can be more sensitive to paper type.

 

[domenan]

Is the paper buffered? Cyanotypes are sensitive to alkaline environments and it looks like there could be some local(or all over) bleaching. If you are set on that paper you may need to acidify the paper to get better results.

I believe Mike Ware’s new cyanotype can be more sensitive to paper type.

Yes, the paper is buffered.
I had the same tough, but the 1st image was pre-treated on a bath of filtered water and citric acid and then dried. As you can see I still got the problem.

 

[koraks]

Try a different paper.

I never found forced hot air (i.e. hairdryer) to be a problem with cyanotypes.

 

[jim10219]

Yes, the paper is buffered.
I had the same tough, but the 1st image was pre-treated on a bath of filtered water and citric acid and then dried. As you can see I still got the problem.

I agree. It looks like the paper is buffered. That's why it came out much better in the example that your pre-treated with an acid bath.

Unfortunately, it can be difficult to get rid of all of the buffer with an acid bath. I usually use hydrochloric acid to get rid of buffers in papers when I want to do a cyanotype layer. I don't recommend you go that route, as it requires special equipment (not only is the acid dangerous to your skin, but the fumes are dangerous to your lungs and eyes, and a strong vent alone isn't enough). But the reason for such a strong acid is because I've found that citric acid or acetic acid usually aren't strong enough to fully wash the buffers out, especially if the paper is kind of thick.

What I would recommend instead is switching to a different paper. There are a lot of papers out there that work fine without an acid bath, and even more that work fine once given a mild acid bath. Look for papers with a baryta layer. Stuff like fixed photographic paper or inkjet printer paper. I find those to hold the most detail and give the sharpest images for cyanotypes.

 

[domenan]

You are probably right. Unfortunately I still have quite a lot of Montval left.
I will try to use the old standard solution, which looks like to be less sensitive to buffered paper then the new one.
I will let you know how it goes.

 

[removedacct1]

I've given up on all of the pricey watercolor papers for use with cyanotype - they all perform poorly in one way or another, it seems. Its probably the buffering agents they use.
I got the best results I've ever had printing on Canson's Marker Pro Layout Pad paper. Its an 18lb hot press paper - very light weight but it doesn't absorb excess sensitizer and renders fine detail like no other paper I've used. Because of its light weight, it does require careful handling when wet, but it gives superior results with the Ware formula Cyanotype. Here's an example:

 

[koraks]

I will try to use the old standard solution, which looks like to be less sensitive to buffered paper then the new one.

Yes, this is certainly true in my experience!

 

[Andrew O'Neill]

Do yourself a favour and get a paper that is meant for alt. processes. If you really want to continue with this paper, then you need to knock out that alkaline buffer with something stronger than citric acid. Sulfamic acid, diluted 10% should do the trick. You can buy it at any hardware store.

 

[Andrew O'Neill]

Even the old recipe will not print well on buffered papers.... That is what I use.