I used corn silk and husk as a brush, but it didn't work so well, so I switched to using the blooms of orange/red marigolds. When the blooms were crushed into the rock they created a red/orange base to my rock painting. I then dipped the left over head of the marigold into smashed blackberries mixed with a bit of oil and covered the figures again to make a darker picture. My cave painting is myself, my significant other, our 2 girls, our 2 dogs, and our cat with a big sun overhead. The first picture is the painting and the second is the paint brushes.