This refers to an open, free, and flexible style of a work of art; it is the opposite of a “densely packed” work of art. Ethereal effect does not mean sheer emptiness; it does not completely avoid imagery, nor does it entirely avoid natural description. Rather its aim is to suggest unlimited possibilities for the viewer’s imagination through a highly economical use of brushwork and imagery so as to pursue the “meaning that lies beyond literal form” or “associations beyond the work itself.” In this way it leaves room for the viewer’s imagination. For example, just as redundant description is deliberately left out of an essay or a poem, along with ponderous wording or unnecessary images, just so thick ink and heavy colors may be avoided in painting. The notion of ethereal effect values simple layout and an economical use of details, seeking to convey character and imagination. Works that make use of ethereal effect convey a wonderful lucidity, and possess openness, freedom, and natural grace. Such works enable viewers to appreciate the aesthetic joy of free imagination.
When painting, classical artists made use of ethereal effect all the more where a dense collection of objects normally was required. However today’s artists no sooner begin to paint than they fill the space with elaborate details. In fact, if a painter applies a few specific details strategically in the empty spaces, then the whole picture will appear more open and alive. Under the circumstances the more images he uses, the less boring the picture. (Yun Shouping: Nantian’s Comments on Paintings)
Some essays are written in a substantive style, whereas others feature an ethereal style. Although these two kinds of writing have their respective merits, they are each lopsided in their own way. But if one reads Han Yu’s essays, he will find that they are a perfect combination of substantive content and ethereal effect. (Liu Xizai: Overview of Literary Theories)