Ink and ink slabs
The traditional ink used for producing calligraphic works and paintings is special too. It is made by rubbing a rectangular or round ink stick on an ink slab with a little water. The ink stick is made of the soot of Tung oil, coal or pine wood, animal glue and perfume. It is viscous but does not coagulate in lumps. Excellent calligraphic works executed hundreds of years ago are still bright today. The strokes done with thick, thin or dried ink are different. Some are black and some are light black. In the eyes of the viewer, they express different weights.