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-   -   Cyanotype Chemicals (http://www.film-and-darkroom-user.org.uk/forum/showthread.php?t=13447)

CambsIan 5th October 2020 05:42 PM

Cyanotype Chemicals
 
Hi All,

With Christmas approaching, I am considering asking Santa for a Cyanotype starter kit

https://cyanotype.co.uk/cyanotype_starterkit.html

Any body know how long the liquid chemicals will last once opened? do they oxidise like developer ?

I know you can buy the powdered chemicals, paper etc from various places, but for a start, I thought the kit might be the way to go.

Anybody got any thoughts ?

Ian

alexmuir 5th October 2020 07:13 PM

Hi Ian,
I just bought the chemicals and mixed the two solutions. They seem to last quite long (months). I have just looked at the book where I found the recipe. The author states that the two solutions, uncombined, will last several months if stored in a cool, dark place.
The recipe I have is ;
Solution A
10g Potassium Ferricyanide in 100ml water.
Solution B
25g Ferric Ammonium Citrate in 100ml water.
You mix equal parts of A and B to create the sensitive solution. This should, apparently be done in subdued light. This is then coated on paper, and allowed to dry, before use. I watched someone demonstrating all this on a TV programme recently, and they worked outdoors in daylight. I’m not sure whether subdued light is actually necessary.
I read somewhere that the process works better on an acidic paper. I haven’t tried that yet, but intend to at some point. The problem is finding any acidic paper. All the stuff aimed at artists is ‘acid free’. I have used watercolour paper successfully.
A kit might be a good idea, but I would be inclined to price the required chemicals, brushes for coating and electronic scales, if you don’t already have a suitable set. You can use things called foam brushes which are inexpensive. You might find that you can buy everything for a bit less than a kit.
The use of Hydrogen Peroxide to tone the images is worth trying. You can buy it from chemists and hairdressing suppliers. You dilute it to 1-2% strength for toning. It creates a more intense blue.
It’s an interesting process, and certainly worth trying.
Alex.


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CambsIan 6th October 2020 09:07 AM

Hi Alex,

Many thanks for the reply.

The items separately add up to a fair bit, and probably more than I should spend on a fist time project.

Glad the chem's last a while before mixing, as reckon it might take me a while to use it all up as sunshine might be in short supply in January.

Once again, thanks for the info.

Ian

Mike O'Pray 6th October 2020 11:10 AM

Yes, it would look as if cyanotype is a late spring to early autumn affair if relying on the sun but there is always a UV lamp at a cost

I had a good look at the site and it was interesting and it does cater well for those wishing to only dip their toes in until they can be sure it is for them.

Mike

Terry S 6th October 2020 11:40 AM

Quote:

Originally Posted by alexmuir (Post 135979)
I read somewhere that the process works better on an acidic paper. I haven’t tried that yet, but intend to at some point. The problem is finding any acidic paper. All the stuff aimed at artists is ‘acid free’.
Alex.

I've only done this process once, when I went on a small local workshop a few years ago now, but definitely enjoyed it. It took place at the height of summer on a sunny day, so it must have been quite a site to see all the participants laying down bits and bobs all over the place outside the building.

But yes, the site looks good and has such an obvious web name that I've not thought of looking at before, but then again I don't know how long they've been around.

As for the kit, I think that's the best way to go initially and then one can top up with items if the process is enjoyed. It would be worth comparing it with some of our sponsors prices, as some of them also stock a kit.

As for acidic paper Alex, I noticed that there's a small packet of citric acid in the kit mentioned. I know nothing of the ins and outs of this process, but do you think that maybe this is the acids purpose in the kit?

Terry S

Mike O'Pray 6th October 2020 11:54 AM

Quote:

Originally Posted by Terry S (Post 135996)

As for acidic paper Alex, I noticed that there's a small packet of citric acid in the kit mentioned. I know nothing of the ins and outs of this process, but do you think that maybe this is the acids purpose in the kit?

Terry S

Yes, I was looking for an explanation on the exact purpose of the citric acid and did a search of the site but couldn't really find anything.

Is it to add to the washing process or to the chemicals to make the cyanotype liquid for coating the paper or for soaking the artist paper which you then dry and thus turning it into acidic paper

Finally if it is for the latter, is this unnecessary if you buy the pre-coated paper which may have been treated?

More questions that answers and a call to the company may be the easiest way to get the info

Mike

alexmuir 6th October 2020 01:04 PM

There are a few kits on the market, but the one Ian linked to is the cheapest I’ve seen, so probably a good starting point.
I don’t know what the citric acid is for. I don’t think it will be to acidify the paper, purely because I’ve never seen that mentioned as part of the process. The reference to acidic papers was either in a book, or on a forum, or other internet resource. I took it to mean that the use of paper with a level of acid in the finished product gave better results than those which are PH neutral. I will try to find the reference.
I used the instructions from a book called ‘The Handbook of Experimental Photography’. I have a UV tanning lamp which I bought to use with this, and other alternative processes.
Alex.




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CambsIan 6th October 2020 02:48 PM

Hi All, many many thanks for your replies, once again FADUer's to the rescue.

The lack of sunshine has had me thinking about alternatives and I had been wondering about UV light bulbs like these

https://www.amazon.co.uk/Equivalent-...NsaWNrPXRydWU=

fitted into my photo light stands with a home made reflector, could this be a "el cheapo" work around for a UV lamp?

Any thoughts

Ian

Mike O'Pray 6th October 2020 02:51 PM

I have searched a bit deeper on citric acid and its use in cyanotype. I googled citric acid in cyanotype printing and it comes up with a whole host of sources. One of the main ones is Mike Ware and he mentions it

In a nutshell it would appear that while citric acid does make a difference in depth of blue it looks to be marginal amount and it can be done without

The problem with research reading is that it can answer some questions but raise others.

One of which may be of interest to those of us who live in areas that have alkaline water( hard water) as opposed to acidic water(soft water) such that Alex is blessed with in Scotland.

Mike Ware warns of the effect of washing in water with PH < 7, saying that water of less than PH 7 must not be used but as there may be people in areas with mains water greater than then I couldn't find what to do about it

I may not have been looking hard enough, mind you and anyway it may not in practice make that much difference in the eyes of the average user

I can find my water hardness in all sorts of measures but not for the life of me can I see anything on converting the water hardness scales into PH

Mike

Mike O'Pray 6th October 2020 03:38 PM

A bit more in terms of PH reduction. If high PH in you tap water is a problem then it would seem the simplest solution is rainwater that is collected in barrels but if this is not practical then de-ionised or distilled water would seem to fit the bill. Both cost money but unless you were to be doing a lot of cyanotypes then the cost might be fairly modest

Finally and I have no idea if this brings any problem to washing cyanotypes is the use of normal household white vinegar. It would appear that as little as a dessertspoon or even less in a gallon of water is enough but again you need a method of measuring its effect such as a PH meter

All of this is predicated by the question - how much does reducing the PH below 7 matter and again I have no idea

Mike


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