Provided is a printhead arrangement having a number of printhead segments arranged to have overlapping print regions, and a printer controller. The controller includes a sensor for sensing a temperature of the respective segments, said temperature indicative of an extent of the overlapping print regions. The controller is configured to supply the segments with half tone patterns for the regions by means of a dither matrix with an interpolation function, such that VA+VB is greater than V where VA and VB are respective independent dither matrix values of a pair of adjacent printhead segments and V is a continuous tone value to be represented in order to reduce artefacts in the overlapping regions.