Here are two versions of a book tour poster for "Rebel Voices," an anthology of texts from the Industrial Workers of the World (IWW). The "Rebel Voices" book cover is an old image of a protest.
I felt that this image was a bit uninspiring and only appealing to history enthusiasts. So I decided to use a historic symbol of the IWW screaming, the sabocat (pictured below). The sabocat has been used as a threat to employers of a "wildcat strike."