Hi! A lovely friend gave me a Cyanotypes kit for Christmas, and now I am obsessed! The kit contained some pre-coated papers, and instructions. Basically, you place flowers, leaves, or any shapes you like, on the pre-coated paper, and leave it in the sun until the paper goes from light green to a dark bronze colour. Wherever the sun hasn't reached the paper, because of the flowers or leaves, that part remains white, and the rest will turn a rich blue.
This was my 1st try. On a cloudy day in the UK, it took just over 5 hours for these to turn the right colour. The blurry one on the right is because i used bulky leaves that weren't flat to the paper. It's better to put a piece of glass over the leaves to keep them flat on the paper.
When they're done, you carefully rinse the paper for a few minutes, then leave it to dry, and it turns a rich blue.
The next day was sunnier, so I put some in the garden, and they were done in about 45 minutes. I used picture frames this time, placing the items on the glass (picture frame facing down), then placing the reactive paper on top, and clipping the frame together. This kept everything in place, and also meant that the paper wasn't face up, reacting to the light, before I'd finished laying things down.
This time, as well as using flowers, leaves and a stencil, I tried negative images, printed on overhead projector sheets. You can use photos or any other images, just turn them into a negative image in Photoshop or similar. I'm pleased with the cat image, but the wolf didn't turn out very well. I think I left it in the sun for too long.
Obsessed now, I wanted to try this with fabric, so I could make them into bags! I also splashed out on a UV light, so it was easier to work out exposure time. That's probably not necessary if you live somewhere sunny!
The pre-coated paper kit was from here: https://www.etsy.com/uk/listing/1513846162/solar-printing-craft-kit-cyanotype-kit
There are loads, though, just search for Cyanotype kit or Sun Printing Kit
For the bags above I used pre-coated fabric sheets: https://www.amazon.co.uk/gp/product/B010MN3K4W?th=1
You can mix your own reactive solution with these two chemicals, and use it to coat paper, fabric, wood, etc: https://www.amazon.co.uk/gp/product/B010MN312S
There are loads of really good youtube tutorials, but I love this one. It explains everything you need to know, including using fabric: https://www.youtube.com/watch?v=KCj1saibrJY
There's also a technique called wet cyanotypes, where you coat your paper or fabric and then use it while the coating is still wet, to get some great textures. You can add vinegar, termeric, alsorts of stuff to add colour and effects. I haven't tried this yet, but I can't wait to have a go! Again, there are loads of tutorials, but I love this one: https://www.youtube.com/watch?v=mpw1qXzKDFk&t=5s