Cyanotypes

Cyanotypes were invented in 1842 by Sir John Herschel. As you can see it's a monochromatic process - but instead of being "black and white" it renders the image in shades of blue. If it looks like a blueprint, there's a reason for that, it's basically the same chemistry.

To make one, you have to get some 100% rag cotton paper and the sensitizing fluid (which I make up in a local college's chemistry lab) and a glass rod or a brush. You use the rod or brush to evenly coat the paper, and let the paper dry for an hour or two. Then you take a negative the size of the final print and place it on the paper (usually in some kind of frame to hold it together tightly). Then you walk out into the sun (or use a UV exposure system) and expose it. The image appears while you wait!

To develop the print, it's possible to just rinse them in water for 20 minutes, washing away the unexposed material. But for best results most professionals use some kind of acid bath first. I use a 30 second dip in very dilute hydrochloric acid which really brings out the blues. Over the next day as the print dries it "matures" a bit and the colors are stronger. Some people rinse the final print with a little hydrogen peroxide to see the results right away but it makes no difference to the final print.

Obviously you need a bit of patience and I've glossed over lots of technique but the results are well worth it!

 

Tea Toned Cyanotypes

To tea tone a cyanotype, you soak it in a bleaching agent (I use ammonia) for a few minutes. It's important to keep the fluid moving or you'll get trapped air bubbles leading to spots. This is unfortunately incredibly dull and stinky which is why I don't do it more often. When it's ready the print turns a kind of ugly yellow-brown. On some images I'll stop this before it's complete to keep some blue in there.

Then you soak it in anything that contains tannic acid - tea, coffee, grape tannin (used in winemaking). This can take an hour or two depending on how strong you made the solution. Then rinse! Since it often stains the paper as well as making the color come back, it gives the whole print a lovely antique feel.

Depending on what you used, the colors will be different. Tea is more bown shades whereas coffee is more black. It's also possible to turn the print a very interesting purple/black color if your solution is rather acidic (easy if you're using straight tannic acid or grape tannin). It's really just a matter of personal preference.

Tea toning can be very nice but it adds at least an hour or two to a process that's already pretty labor intensive. I've had prints take as long as 10 hours to bleach and tone properly. Still, they look great and it certainly lends some variety to the process.

One detail is that by the time a print has gone through all the cyanotype steps and all the tea toning steps, it tends to be pretty soggy and fragile. You have to be very careful not to rip the paper!

 

Van Dyke (Vandyke)

The Van Dyke process is a member of the Kallitype family of processes. It produces images in a lovely brown shade. The Van Dyke process isn't as sensitive to paper as the Cyanotypes so it's also possible to use watercolor paper with more success. However I've found it better to just stick with my 100% rag cotton platinotype paper.

To make one it's a fairly similar process to the cyanotype, at least conceptually. You take some paper and some chemicals and coat the paper evenly with the chemicals. You use a negative the size of the final image, put it in a contact frame, and expose it to UV light.

The whole development process is a little more involved. You do a water rinse which removes unexposed material. Then you put the print in a sodium thiosulfate (hypo) fixing solution to really develop the print. Then you do another wash cycle to get the developer out. If you're already doing an acid step for your cyanotypes it's roughly the same level of complexity - three steps instead of two but the rinses are shorter.

There are a variety of toning techniques that will work with Van Dyke prints - including with platinum which is very archival.

 

Ziatype

This is a relatively new platinum/palladium process - it's based on some older techniques but with some modern refinements. It differs from traditional platinum in several ways, but the key ones are that it develops out as you expose which I prefer, and it gives you a lot of tonal control. You can get very cool black or more warm sepia tones by fiddling with the chemistry a bit - it's very flexible. You can also add gold chloride and introduce some blues or purples into the mix.

To use this technique, you get a shot glass and carefully use an eyedropper to add sensitizer, palladium solution, possibly platinum solution, toner, contrast enhancers, whatever you want. Then you mix it all up and spread the fluid on the paper using either a glass rod or brush.

The somewhat tricky bit is Ziatype is very finicky about humidity. Here in California that usually means running a humidifier and watching a humidity meter. You want the paper kind of limp but not so wet that it will hurt your negative. I've found if I can keep the room at 65% humidity things go very smoothly.

If you have that right, it's easy from then on out. You can simply expose the paper "until it looks right" (although I have everything calibrated out so I always use the same time) and while you don't need a developer as such, you do need to wash out any unexposed fluid. This usually means a water rinse, followed by soaking in some kind of clearing agent (citric acid works, so do traditional platinum agents - I do multiple trays just in case), followed by more water.

 

Traditional Platinum

sample platinum image

The biggest difference versus Ziatype is that Ziatype is a print out process (POP) and traditional platinum is a develop out process (DOP). So there's an extra step here. You get a really faint image after exposure and you have to take another tray and dump some developer over it before the image will appear. It's very cool when that happens though - the image appears instantly, almost out of nowhere. Like most printers I use a mixture of platinum and palladium to get the exact look I like, and the mixtures are different with the two processes, but the end effect is the same.

sample platinum image

The good news is that while you want the humidity to be in some reasonable range, it's not nearly as critical as with Ziatype.

I use both platinum/palladium processes as the mood strikes and depending on the humidity that day.

 

Cyanotype Over Platinum

sample cyoplat image

If you're really a glutton for punishment, you can print a cyanotype right on top of a platinum print and get some very cool results. (It usually isn't done the other way - for one thing most platinum developers don't play well with the cyanotype chemistry.)

One problem is that the paper shrinks a bit when you wet and dry it (no surprise, it's cotton) so you have to preshrink the paper, press it flat, print a platinum layer, press it flat, print a cyanotype layer. It takes me about a week.

sample cyanotype over platinum image

The other approach is to get sneaky and instead of pre-shrinking the paper simply print a negative for the cyanotype the size of the shrunken image. If you have a very consistent paper this actually works very nicely, but if you're making more than one of the same image with inconsistent paper you're going to make a lot of extra negatives, and if you've measured wrong by even a tiny amount you can see the difference (we're talking about a hundredth of an inch here).

The images are lovely - you may not really be able to see the difference versus a cyanotype on your monitor but instead of Prussian Blue the images are a lovely silver-blue and really dark areas are more of a true black instead of just being really dark blue. Almost nobody does this process on a regular basis because it's so much work and because you have to be very comfortable with two historic processes to even consider it but the results are worth it once you get it figured out.

 

Paper Types

All of the other images on this page are on COT320, an expensive French cotton paper originally developed for fiber base silver gelatin photographs. However, one of the nice things about these processes is that you can make prints on a variety of papers.

This image is a cyanotype printed on papyrus. Papyrus is a highly variable paper, but I think it looks very nice with cyanotype. I don't do it very often partially becaue papyrus really doesn't want to dry flat but the results are always very cool.

This image is a Ziatype printed on Kozo paper, which is a handmade Japanese paper. Kozo is the inner bark of mulberry tree seedlings and is used in a variety of traditional Japanese crafts. It also makes an interesting photographic paper. It's very strong even though it's super thin - if you hold the paper to the light you can see the print from both sides and you could blow your nose with it, no problem.

One thing I need to figure out before I sell any is how to photograph it - I tried a velvet background so you could see the edges, but it shows right through the thinner areas (the background is more white than it looks here.) I'll have to try white next time. Also the paper has a lovely sheen which comes through in a photograph as glare. But figuring this sort of detail out is all part of the challenge of making obscure kinds of prints and selling them online.

 

Masked or Unmasked?

Usually I leave the edges of the image "unmasked" or partially masked meaning you can see the edge of the area I coated, giving it a more handmade look. The more square edged images were coated with a rod. If I coat with a brush usually the edges have some visible brush strokes. In this case I've masked out just a bit of an edge around the image and a signature line, giving the customer options to see the marks or just mat over them while allowing the signature to be seen. (If they're totally unmasked I have to sign below the marks which looks fine but allows fewer options).

However it is also possible to totally mask off that piece of the image with cardboard or other opaque material (rubylith works great) so that you get a more even edge. There are several techniques to do this which will give you harder or softer edges.

It is also possible to offset the mask or use a somewhat oversized mask to leave a border around one or more edges but not the others. This is sometimes nice on an image with a very pale background to set it off a bit. It's also possible to use an oval mask or basically whatever you want - one of the great things about these processes is you have a lot of control over the end result.

How To Purchase

Most images are available for sale in cyanotype and platinum (my choice of Ziatype or traditional) via my shopping cart system. If you use this system I'll make one as soon as possible and send it to you but obviously this will take a little while. I have a newborn so this might require some patience on your part.

Images "in stock" can be found in my eBay store - that's much faster and at the moment cheaper (I left the "in stock" items alone when I recently increased prices).

If you want an image made by another process please feel free to send me an email and we can discuss your options.