Stencilling is an ancient technique. Stone age people already sprayed ocker over their hands to leave an individual handprint. In the 1920s it was used in France for book illustration and even public authorities, military and companies use this technique to mark property quickly and uniformly.
A stencil is made with shapes that are usually made of paper, cardboard or plastic foil; the artist draws the image and then cuts it out. After that, spray paint or roll-on paint is used to create the artwork on the surface.
The father of european stencilling is probably Xavier Prou aka BLEK LE RAT, who use stencils instead of stylized lettering for graffiti. A giant graphic image of a rat, which he placed all over Paris made him famous. From small and simple stencils he developed to bigger formates and multilayer stencils.