On the infamous separation barrier between Israel and the Palestinian West Bank, street art meets politics as artists including Banksy, Blu, Ericailcane, Faile, JR, Know Hope, Paul Insect, Ron English, Sam3 and Swoon leave have left messages for all to see. The walled part of the barrier is full of their scribbling, paintings, stencils, graffiti and posters. Combining pictures with interviews, Concrete Messages looks into the politics behind their art and their motivation for choosing the separation barrier as their canvas.