I'm loving this! It reminds me of leaf spots in Autumn.
It's the result of indian ink being dripped onto wet paper to cause a reaction, the paper was dried and then over-dyed with a wash of walnut dye. The pic below shows my son making one of his indian ink/water papers which we did a few weeks ago. I saw the potential for good collage fodder so made myself a few too! He graciously donated me his papers as well:)
ICE #12 is nearly finished. It was inspired by a game of snakes and ladders and uses a large piece of my lined eucalyptus paper so watch this space!