The Turkish art of paper marbling. The ebru artist creates colorful patterns by sprinkling and brushing pigments on a pan of oily water, then transferring the resulting pattern to paper.  Ebru is believed to have been invented in 13th-century Turkistan, whence it  spread to China, India, Persia and Anatolia. Seljuk and Ottoman artists used marbling to decorate calligraphy, books, tughras, and other official documents. Web resource here.