An anthotype is an image created using photosensitive material from plants. This process was originally invented by Sir John Herschel in 1842. An emulsion is made from crushed flower petals or any other light-sensitive plant, fruit or vegetable. A coated sheet of paper is then dried. Place some material, for example leaves or a transparent photo positive on the paper and expose to direct full sunlight until the image part not covered by the material is bleached out by the sun rays. The color remains or fades in the shadowed parts.--- (wikipedia)
This one is tomato leaf juice, which makes a nice dark green and takes only a couple of hours to bleach, changing to brown
@imnorman i have read that there is no way to fix it, the colours you can get are so varied and beautiful, just keep in a place without direct sunlight.
@bella_ss you dont need the additives, if you have a mortar and pestle or even rubbing two rocks together, just add a few drops of water to get enough to put on a paintbrush, i didnt even strain it, just rubbed off the lumps with some paper towel
And this. Will try it my self alas at the moment all vegetation dormant.
have added a link to step by step instructions, in case anyone wants to have a go