Ever since I was introduced to the Cyanotype process during my degree, I’ve loved it’s unpredictable, painterly qualities. The process dates from the 1850’s and so is about as far away from what I’m currently doing with the iPhone or Photoshop as it’s possible to get. To give my Botanical Gardens students a taster of the thrill of seeing a photograph all the way from the taking stage to the final print as one would in the darkroom – but without the benefit of a darkroom – I have been including cyanotypes as part of the “Beginners DSLR” course for the last few years. I think it surprises people that they can produce such a unique result from a digital image.
Anyway, here’s something you can do without even a negative – a kind of cyanotype photogram – which I have used to make this year’s family Christmas cards. What you will need is…
- Blank white greetings cards with envelopes.
- Watercolour paper. Ideally at least 400gsm. Cut into squares or rectangles of a suitable size to fix to front of cards.
- Double-sided tape, glue or seloptape.
- Cyanotype chemicals: Ferric ammonium citrate* (the green variety) and potassium ferricyanide*.
- Seasonal foil confetti (I used snowflake shapes).
- Piece of glass or picture frame.
- Bristle paintbrush, sponge, or sponge-brush.
- Weighing scales capable of measuring down to at least 1 gram.
Start by mixing your two solutions (separately): 5gm ferric ammonium citrate with 25cl of water, and then 2gm potassium ferricyanide in 25cl water.
In subdued lighting (these chemicals are now light sensitive), mix the two solutions together to make the cyanotype sensitizer and paint or sponge thinly onto your pieces of watercolour paper in whatever way you like – just don’t put too much on, less is more.
Put the sensitized paper pieces somewhere dark to dry. This shouldnt take long – 30 minutes at most.
When dry, and still in subdued lighting, scatter (or carefully place, as you wish) the foil shapes onto the sensitized paper pieces. Carefully place a sheet of glass on top of the paper/shapes.
You can now switch the main lights on. Ideally you’d be able to leave the “printing out frame” outside in the sun to expose but there doesn’t tend to be a great deal of that around at this time of year and so you can either leave it under strong room and/or window light for as long as it takes for the sensitizer (which was originally yellow) to turn a muddy green/grey colour. It is UV light which effects this change so the higher a UV content your light source has, the quicker it will happen. Don’t worry, you can’t really over-expose these prints so better to over- than under-expose. I have a Phillips UV face tanning lamp, bought on ebay for £15 which does the trick nicely. If you have a sunbed, you could use that – just make sure you keep the prints moving around or you may see the straight lines of the tubes on your print.
Once the prints are exposed, remove the glass and then the foil shapes. Wash the pieces of paper in cold water until the water runs clear (the background should look blue and the bits where the foil shapes were should be white). Leave the prints to dry. The blue colour should darken as they dry.
Once dry, stick the prints to the front of your blank cards and you have unique (no two will ever be the same) cards for family and friends.
Other ideas: Use watercolour painter’s masking fluid to paint designs or write a message on the paper before sensitizing rather than (or as well as) using the foil shapes. Or use other shapes for other seasonal cards.
* – Chemicals can be obtained by mail order in pre-measured kits (expensive!!!) or as the raw chemicals from Silverprint in London – http://www.silverprint.co.uk/ProductByGroup.asp?PrGrp=49 These chemicals go a long way so only mix a little at a time. You can store the individual solutions in brown glass bottles in cool dark conditions for a week or more if necessary.