Any surface can be used for a projection: wallpapers, paint, cloth, screen, etc. Choose white or light-colored surface. Projections are hardly visible on a dark background (black, purple, maroon).
Lightning conditions. Projections are best displayed in a semi-dark room. By day, close the curtains; by night, dim the lights. In the daylight, only small projection (1-2 m) can be seen clearly.
For semi-dark rooms, average size of projection is 4 m. Complete darkness allows displaying images 8 m in width using one projector.