Sumi Ink
Sumi ink is made of pine soot and nikawa (animal hide) glue, and is one of the oldest materials known to human history of art. Chinese have thousands of years of calligraphy and painting tradition on paper and silk, and Japanese art has even refined that further in the zen paintings of 15th century on. I have began to use sumi as a symbol of our journey of humility (as in Ash Wednesday liturgical paintings at All Saints Princeton Church installation during the Lenten Season) as Christians are marked on Ash Wednesday with ashes in repentance and in their meditations into our mortality.