1. A method of reducing show-through error in duplex printing comprising: determining at least one of sizes and locations of a first side image and a second side image of a duplex-printed image recording medium; determining an amount of residual magnification error based on the determined at least one of sizes and locations, the residual magnification error related to shrinkage of the image recording medium; and determining margin shifts that reduce show-through error due to at least the residual magnification error based on the determined amount of residual magnification error; wherein the determined margin shifts can be subsequently applied during printing of image data to reduce show-through error.