A similar question was asked on the French leg of this site. My conclusion was the same as yours. LO Writer incorrectly dos not remove XML element <draw:fill-image name="xxx"> when you reset background image to none. What is worse is that Writer uselessly duplicates binary data for the image as content of the XML element. I write "duplicated" because there is some kind of image catalog at the start of the file in <office:styles> as elements <draw:fill-image draw:name="xxx"> containing binary data. The "xxx" is the same in the catalog and <draw:fill-image name="xxx"> .