Stencil
thin sheet of material, with letters or a design cut from it, used to produce the letters or design on an underlying surface
A stencil is a blocking material used to mask a surface. In it there are holes for ink or paint to pass through. That way an image is made on the material behind the stencil. Stencils are used when many copies are needed of the same image. It is used in street art, and many public notices.
Screen printing is a printing technique using a fine mesh. Ink is applied except in areas blocked by a stencil.