This limited set of ATC's (artist trading cards) was made with the bark of a Paper Tree. The Chinese characters were made with ink and rubber stamps. The symbols are nature words like tree, garden, spring and leaf. I found the rubber stamp set at my local Barnes & Noble bookstore for $20.00. The bark was glued, using a spray adhesive, to recycled cardboard and cut into 2 1/2 X 3 1/2 inch pieces.