One layer at a time

"Woodblock water printing is not determined by what you can see," says Li Yang, a Rongbaozhai practitioner who has worked in the field for about 20 years. "It is determined by what you cannot see."

A clearly defined line can be traced. A distinct patch of color can be carved and printed. But what happens when it comes to something that appears to have no definite boundary, like watery halos, subtle washes of color and barely perceptible transitions?

"If the printer reproduces such details too literally, the result can become stiff and mechanical. If they leave them out, the copy may lose something essential to the original.

"There must be a balance between faithfulness and expressiveness," Li says.