1. An image forming apparatus for overlaying woven pattern data to document data received from a host apparatus and printing, comprising: a woven information table having pre-stored woven information corresponding to respective characteristic information of document data; a discriminating section configured to discriminate characteristic information of the received document data; a selecting section configured to select the woven pattern data, on the basis of the characteristic information and the woven information table, for overlaying on the received document data to print; and a print controlling section which overlays the selected data and said document data to print.