I'm trying to expose my first cyanotypes this morning. I used the Photographer's Formulary liquid preparation. They are exposing on top of a cutting board with a piece of glass on top of the whole sandwich, in my apartment next to a window. It's a cloudy day and we're expecting snow. I waited about an hour this morning and then I had to go to work, so I just left it there. It will end up having hours and hours of exposure. But by the time I left there wasn't the slightest change in the color of the dried coating elsewhere on the paper. So my questions are -- how long should I expect these exposures to take under these conditions? Can I use the coated margins of the paper as a decent indicator? If I end up really overexposing these, can I bleach back some contrast? And finally, if I've coated the paper excessively will that make it take longer? Thanks.