Basic cyanotype advice needed please...

[vickersdc]

This is great stuff, and really interesting

Just a very quick post, to show you the image that exposed on to the paper sized with normal food-grade gelatine, and with arrowroot brushed over that once dry. The paper is my own handmade concoction!

So, not a successful image - but at least there's something there! In fact, I couldn't believe a) how dark the image went, and b) the sharpness, which appeared to be much better than coating the commercial paper with just the sensitiser.

Cheers,
David.

 

[Loris Medici]

Evan, expose the glass coated with dichromated gelatin from the back. And do not expose it for long; 30 secs to 1 minute is pretty much enough for a usual lightsource consisting of 20W 24" UVBL tubes... Dichromate stain is caused by / will worsen with over-exposure.

David, you're getting close... In any case, I'd rather prefer to learn the process by using good tempered commercial paper and then modify my procedures to suit own hand-made paper. There are just too many changing variables right now.

Regards,
Loris.

 

[banana_legs]

Loris,

Thanks for the exposure tip, I had noticed that over exposure made washing harder but had not thought of exposing from the back, hardening the most important part first.

David,

The image is looking very promising, I am not surprised by the depth of the blue as I can achieve similar results. If you want to control the variables in printing, consider cutting one sheet into many small pieces so that the support and size is identical for each test. The process is easier for commercial paper as you can get a nice big sheet to begin with. With hand-made paper, I am limited to 8"x10" at the moment (unless I make the paper in the bath!) and I do not get many test samples per sheet. As for the resolution, it is really down to the degree of contact between the negative and the cyanotype; this seems to includes exposure into the material itself. I had some paper where I coated it with gelatine and then used an alum bath to harden it, then put a thick un-hardened gelatine layer on top. The cyanotype mix did not soak into the paper much but was absorbed by the top gelatine layer. I then contact printed with a negative printed on a laser printer with a 1200dpi mask. Every dratted laser dot was visible with a loupe! If the cyanotype solution soaks into the paper, I noticed that the dots began to blur more; my hypothesis is that the sensitiser deeper in the paper is not in direct contact with the negative and so some resolution is lost. With a different laser printer giving 600dpi, even well soaked-in cyanotypes seem capable of re-producing every dot. As my paper is quite rough, I tend to get regions where the dots can be seen on the 'ridges', and in the 'valleys' the dots blur and a smoother tone is present. I have reverted back to film negatives where I can and ink-jet for any digital negatives.

Best regards,

Evan

 

[vickersdc]

Thank you both for your encouraging comments!

Evan, I like the idea of making larger sheets, but I'd have to make a new mold & deckle first! Not a big issue, it's just finding the time! On the piece of paper that got completely ruined, I had used a Blanchard brush to apply the arrowroot, but it just didn't go on well at all; however, changing over to a brush did allow me to slightly work the arrowroot and get a more even coating. Certainly coating larger sheets would be less wasteful than at present.

I was quite surprised at just how sharp the image can be, and there is certainly more detail than I had expected too.

This is brilliant, I'm really enjoying trying all this stuff out

 

[vickersdc]

So, after many months of not picking up the camera, and no photography at all; I've finished the build of the 9x12 camera and tested it(!), and today I've been making my own paper again.

I'm really limited for available time, but I'm hoping to build up a stock of home-made paper to use for cyanotypes in the near future (around Xmas time perhaps?).

Cheers,
David.

 

[Jerevan]

Ah, it's Mr "Blanchard Brush" himself! I read the thread and to tell the truth, you are truly a mad hatter! (in the Lewis Carroll sense)

Making cyanotypes and making your own paper and building the camera - that's impressive! Have you finished the camera? I looked at the Flickr and it looks beautiful even in its almost-finished state.

 

[vickersdc]

Jerevan, that post was the best thing I've read all month! Fancy being likened to Lewis Carroll - well, the Mad Hatter at least!).

The camera is done and to be honest it doesn't look a whole lot different - just blackened the insides and waxed the outer. Works a treat... but version 2 is being planned*.

Funny enough, I was just chatting to the wife, saying that it'd be satisfying to take a picture with a camera that I built, on a glass plate that I've poured the emulsion, then use the printing frame that I made to print on to paper that's also home-made! Lord only knows what the result will look like mind

* V2: this will allow me to choose portrait or landscape by switching the back around, and will acccept either plate glass or tintypes.

 

[Jerevan]

It sounds like there's a good bit of adventure left in here!

I think the results from a plate on some handmade paper, given a little time and experimentation, will be great. I am looking forward to version 2.

 

[vickersdc]

It sounds like there's a good bit of adventure left in here!

I think it's safe to say that there may be some failures before a success - but that's part of the fun!

 

[vickersdc]

I've slightly modified the Blanchard Brush... and it works beautifully

I've just coated 12 sheets of handmade / homemade paper with an arrowroot solution and they're currently hanging across the hallway from a piece of string to dry! (Personally, I'm waiting for the wife to come waltzing out of the lounge and get a face-full of arrowroot...)

 

[vickersdc]

Well I tried coating some of my home made paper today and exposing under my new (to me) UV light, but the paper just disintegrated during the wash. I´ve now just coated the remaining sheets in gelatin / chrom alum to further size them. I also thought I´d give cyanotype on glass another go, and I also sized some zinc sheet too as I fancied trying cyanotype on to metal.

 

[vickersdc]

As expected, the cyanotype on glass only left a very faint image - I never could get a decent cyanotype on glass! I can't work out if I need a thicker coating of gelatin, or multiple coatings of cyanotype.

As for the metal, well here's the image...

This was a zinc sheet, coating it with an acrylic gesso then a traditional cyanotype mix (with added citric acid). That yellow on the image is the solution that I just couldn't wash it - it really wouldn't shift, so it'll be interesting to see what will happen over the next few weeks / months...

I note that gesso is also alkaline and that's probably not ideal for cyanotype permanence, and I've just coated some glass and more zinc plates with it (using a glass rod to give a smoother surface). As I've still got some gelatin made up from last night, I might just overcoat the gesso with gelatin once it has properly dried.

 

[R Shaffer]

Well I tried coating some of my home made paper today and exposing under my new (to me) UV light, but the paper just disintegrated during the wash. I´ve now just coated the remaining sheets in gelatin / chrom alum to further size them. I also thought I´d give cyanotype on glass another go, and I also sized some zinc sheet too as I fancied trying cyanotype on to metal.

If the additional sizing does not work, have you considered mounting the paper to one of your zinc sheets?

Either way, looks like fun.

 

[Hexavalent]

Well I tried coating some of my home made paper today and exposing under my new (to me) UV light, but the paper just disintegrated during the wash. I´ve now just coated the remaining sheets in gelatin / chrom alum to further size them. I also thought I´d give cyanotype on glass another go, and I also sized some zinc sheet too as I fancied trying cyanotype on to metal.

Does your "home made paper" incorporate internal sizing? AKD helps to bind the fibers and lend a little more wet-strength. It should be incorporated in the wet-end for best results.

My preference is for gelatin hardened w/aldehyde - no staining, no residual salts, and very little swelling.

 

[vickersdc]

My paper has no internal sizing - originally I had added the arrowroot for that purpose, but it quite clearly made no difference! Anyway, I'm pleased to report that a couple of smaller pieces (that had been arrowroot'ed), had the gelatin / chrom alum size added (dipped into the solution). I then exposed these as normal and started to wash them. Then I ran out of time, so I left them in a slightly acidulated water bath for about 4 hours! They were fine, actually it was really handy as I was having trouble clearing all the solution out

Hopefully this week I'll get a chance to put the gelatin over the gesso (on the zinc sheets and the glass) and see how that goes.

Thank you for your replies.
David.

 

[vickersdc]

I've now done the gelatin and gesso thing, and had a mixed result (most likely due to my own inability to wait the required amount of time!).

Using the glass rod for the gesso was, even if I say so myself, a moment of pure genius The final image looks loads better for not having all those brush strokes running through it!


I mixed up a gelatin / chrom alum solution and coated the gesso & zinc sheet. This did almost completely eliminate the problem with the gesso wrinkling up when put into water (I washed the image in a small plastic food tray). The image washed out quickly too - nothing like as long as I did when just using gesso. Unfortunately for me, I didn't wait a full 24(?) hours to allow the gelatin to harden and one patch did wash off

I'll wait a bit longer until I do the remaining zinc sheet and glass plates! Overall though, I'm rather pleased with this attempt, despite it's obvious imperfections, and I hope the gelatin will act to buffer the cyanotype from the alkaline gesso.