In an example, a method includes receiving print data indicative of an image to be printed on a substrate. The print data may indicate an image portion in which an image is present and a void portion in which the image is absent. An amount of background print agent to be applied to a region of the substrate corresponding to the locations of the image portion and the void portion on the substrate when the image is printed may be determined. In examples, the amount of background print agent determined to be applied to a region of the substrate corresponding to the location of the void portion on the substrate when the image is printed is greater than the amount of a background print agent to be applied to the region of the substrate corresponding to the location of the image portion on the substrate when the image is printed.