Yup! This is a weird one! * I use ketchup, but other dark viscous liquids should work! Other images that look similar may work as well - inverted photos of clouds for exmaple. Feel free to experiment!
I love TTRPGs (Table Top Role Playing Games) and they require a lot of mapmaking, so i developed a way to randomly generate good looking maps!
1. Place some separated dots of ketchup on a thick napkin/paper towel.
2. Fold and crush the napkin randomly. * don't crush entirely or else it'll make One Big Blob.
3. Take a photo!
4. Transfer photo to Clip Studio Paint
5. Edit the photo so the napkin takes up the whole canvas. * 2500px + on the smallest side is ideal.
6. Open your auto action window and use it!
7. (Optional?) Clean up the map! erase edges and edit with a rough edged brush.