ground: (art) the surface (as a wall or canvas) prepared to take the paint for a painting
surface: the outer boundary of an artifact or a material layer constituting or resembling such a boundary
stencil: a sheet of material (metal, plastic, cardboard, waxed paper, silk, etc.) that has been perforated with a pattern (printing or a design); ink or paint can pass through the perforations to create the printed pattern on the surface below