We often get asked the question "How long will it take to expose my cyanotypes in the sun?" and the answer to this is always "It depends."
With winter drawing is and with not much sunlight we want to give some pointers on how long it will take to expose your cyanotypes in the winter sun.
If the weather permits and it's not raining exposing your prints outside is always preferable. The best time for exposing is around noon, between 12 o'clock and 2pm, this is when the sun is the strongest. Put your paper in a sunny spot. Exposure times will vary between 10 minutes and an hour depending on time of day and weather conditions.
If it's raining you can always try and exposed inside. If you do this you need to put your paper where it will get the most sun, propped up by the window and expect long exposure times, even a couple of hours.
Watch our video of a winter sun exposure, see how the colour of the coated paper changes from light to dark green, and when it's ready a silvery colour. This video was made on the 1st December at 1 o'clock on a sunny day, and the exposure took 15 minutes.
Below are some images that show different exposure times to give you an idea of how long it could take you to expose in the winter sun.
Below step test and exposure at 1 o'clock partly sunny day, exposed time 20 minutes:
Afternoon exposure 3 o'clock, 30 minutes, cloudy weather. This is a bit late for a winter exposure, the sun started to go down, not fully exposed:
Exposure in the window, facing the sun on a partly cloudy day 12 o'clock. It took a couple of hours but fully exposed: