Abstract: Examples of light guides for printing devices are described. In an example, a light guide may include a substrate having a first end to receive light emitted from a light source. The light guide may also include a second end to output diffused light, based on the light received at the first end. Further, the substrate has a bend profile disposed such that the light entering the substrate through the first end is reflected towards the second end by an inner surface of the bend. In an example, a ratio of a length of the substrate to a width of the diffused light at the second end is in a range of about 1:6 to about 1:12.