For months, I've been looking slightly fascinated at cyanotype prints. I was first exposed to them through Britta Hershman. I loved the subdued and slightly uneven rendition. So when the opportunity arose to take a lesson with Sinead last time I was in Ireland, I totally jumped on it.
This post aims at describing the process for those who may be curious or intimidated by it. It turned out to be so easy that I intend to do some more Cyanotypes with my kids as soon at time and weather allow. I'll break it down in steps for easier understanding:
1. What you'll need
You need a few things for the kind of Cyanotype I was shown how to do:
a. a digital photograph, if possible a contrasty one since cyanotype doesn't do subtle very well
b. an inkjet printer and some inkjet film. Printer quality is not an issue here, see below for why
c. a bottle of cyanotytpe sensitizer (I used Fotospeed Cyanotype Sensitizer). Some people also like to do their own, but I'm not there yet.
d. art paper, preferably hot pressed to avoid too much texture in the paper. I used two types of paper: Seawhite Cold Press Watercolour and Fabriano Artistico. You want it fairly thick, around 350g.
e. a glass rod (ideally the width of your paper or thereabouts), a syringe (with smooth action if possible) and a glass plate 6mm thick and larger than the print you intend to make.
f. a little bit of citric acid. This can be found in oriental or middle-eastern groceries as they use it frequently for taste enhancement in dishes.
g. direct sunlight. Don't plan this on a rainy day, you'll be dissapointed.
Please note that Fotospeed has a Cyanotype Kit that had everything you need (except sunlight). I'm not advocating you should buy it, but I will be getting it, especially since I haven't found the glass rods on sale individually anywhere else.
There are two things you need to prepare: your paper and your digital negative. Both are easy.
For the paper, you need to be in a dim place with no direct sunlight (but you don't need full obscurity either). Lay the paper flat in front of you and position the glass rod alongside the short side of your sheet (assuming an A4 sized print or thereabouts). Then fill the syringe with sensitizer and gently press it at the junction of the rod and the paper all along the width of the rod. You want to be fairly quick at this so you can spread the fluid on the page before the paper absorbs all of it. Then push the rod away from you, thus distributing the sensitizer on the sheet. If you don't have enough fluid for the whole area you want covered, do it again as evenly as you can. Being even here is not vital, but it will enable a fairly homogeneous printing process. If you distribute the fluid unevenly, different parts of the picture will have different levels of intensity. Similarly, if you use a brush instead of a rod, you'll be adding some texture to the print from the brushes. That may be desirable or not depending on tastes (note that it'll require more fluid for a page as the brush will drink some of it.) Once your sheet or sheets are ready let them dry for at least 30mn in full darkness.
For the negative, you'll need to load your photo into a photo editing software (photoshop, elements, gimp, etc.) and convert it to black & white. If the contrast isn't too high on the shot you can bump it up, and then you need to invert the picture so that the black areas become white and the white black. That's your negative. Print that out on your inkjet film. The reason you don't have to bother about the printer quality is that the printing process is way more lossy than the quality degradation you may get from any modern inkjet printer.
Once you have your negative and your paper is dry, it's time to expose the paper to the sun. Align your paper and your negative, ideally on a hard surface (like a wooden board) and clamp them all together with the glass plate on top. Your sandwich should be (from bottom to top) wooden board > coated paper > negative > glass plate. The reason the clamping is important is that once everything is exposed to the sunlight, if the negative moves in relation to the paper, you'll get multiple exposures.
Once your sandwich is ready, bring it outside into direct sunlight and watch the paper change colors. This can happen real fast or slow depending on the time of day, occasional clouds, etc. but generally 5 minutes in direct sunlight should be ample time for the process to happen. Sinead told me that there's a point at which the blue of the revealed areas takes on a yellowish tinge and that's when it's ready, but I need more repeated experience to be able to spot that moment.
4. Final Steps
Unclamp your sandwich outside of direct sunlight and submerge the paper in a bath of water and citric acid (sprinkle and let dissolve while your pics are exposing outside, ideally). You should move the paper around regularly for about 5 minutes, and you'll see detail emerge and contrast increase during this process. It's really a magical moment.
Once that's done, put the paper under the tap for about 20 minutes. The running water will wash away the remaining sensitizer, which is vital if you don't want your photo to keep developing over time as it's exposed to light and end up completely monochrome.
Finally, hang your paper sheet somewhere it can dry, et voila!
As you can see from the photos below, the choice of paper had a huge impact on the contrast in the shots I did. The Fabriano Artistico led to highly grained and contrasty shots whereas the Seawhite led to deep blue low contrast shots. I don't really know why, but I plan to experiment with different papers in the future.