Here’s how it works: when the cyanotype fabric is exposed to sunlight, a chemical reaction occurs. It won’t reveal itself, though, until you put the fabric in water. Then it will instantly turn blue!
So how do you make a print? Place objects on the fabric to block the light: anywhere the sunlight doesn’t touch will remain white and leave a photographic impression on the fabric (this is called a “photogram”). To make prints of photographs, just print the photo onto a transparency* and place that on top of the fabric instead of an object. You can even make prints from drawings by first drawing on a transparency—the possibilities are endless! Exposure time depends on conditions, but is generally 3-10 minutes.