An air knife for separating media from a roll in an image forming system includes a body; a first air plenum; a first plenum passage fluidly connected to the first air plenum; a first exit passage fluidly connected to the first plenum passage; a first air exit fluidly connecting the first exit passage to an outside of the body such that the first air plenum is fluidly connected to the outside of the body through the first air exit; a second air plenum separated from the first air plenum such that fluid in the second air plenum is separated from fluid in the first air plenum; a second plenum passage fluidly connected to the second air plenum; a second exit passage fluidly connected to the second plenum passage; and a second air exit fluidly connecting the second exit passage to an outside of the body.