Examples include estimation of pen to paper spacing (PPS). Examples include an alignment pattern printed on a medium at a target speed, an optical scan procedure performed on the printed alignment pattern to determine values of cross-media misalignment for first and second portions of the alignment pattern, determination of a dynamic swath height error (DSHE) effect value based on the values of cross-media misalignment, and estimation of an amount of PPS based on the determined DSHE effect value and the target print speed.