Without a doubt, stencils are the fastest, easiest, and cheapest method for painting an image on a wall, a sidewalk, or almost any object anywhere.
Stencil Nation focuses on the unexpected mix of this lively, accessible medium to reveal engaging aspects of an intentionally secretive international creative community. With dynamically illustrated perspectives from diverse niches of the art form, hundreds of photographs and numerous essays have been curated by StencilArchive.org's founder, Russell Howze.
Russell Howze is the author of Stencil Nation and the founder of StencilArchive.org. He saw his first stencil in 1990 in Clemson, SC. When he landed in San Francisco in 1997, he found dozens on the sidewalks of the Mission and Haight neighborhoods.
He's never stopped photographing the sometimes temporary, always intriguing art form. He currently lives in San Francisco's Mission District.
I never realized that stencils had so much history or even that they were that old. Some of the work is very impressive. Wiki has a good description of the history and related facts as well: http://en.wikipedia.org/wiki/Stencil