I have often used real wall paper. As others have said, hard
cover with at least a prime coat of paint, never soft
cover flats. The paste is a water
base wheat paste so it can be taken off with warm water and a little time and labor.
Depending on the show, the design concept and the
stage size and distance from the audience, look for a LARGE
pattern. Scale is usually too small for good
stage use. However, some patterns will have a large
pattern laid over a smaller one. Plan on some paint work over the paper to tone and adjust the background for light from a window or other "apparent" light source, to darken an alcove or add shadows as if you were doing a scenic job. Think of transparent washes or subtle
spatter jobs. Wall paper doesn't completely eliminate painting, but it makes a highly ornate job easy and quick, saving hours and even days of paint time.
If you find large patterns over laid, the right
wash can make one
pattern or the other
fade or almost disappear so it "seems" like one large
pattern. Some times a single, deep color, brush stroke or two in the same place of each
pattern can enhance or "change the
pattern effect. HTH.