Sentence:  Instead of isolating the literal flatness by specifying and circumscribing it , the pasted paper or cloth releases and spreads it , and the artist seems to have nothing left but this undepicted flatness with which to finish as well as start his <WSD>picture</WSD> . 
Meaning of the word marked with <WSD> tags:  graphic art consisting of an artistic composition made by applying paints to a surface