As watermarks were actually listed in the 'whats new' when the new grids were first announced, I was surprised how hard it was to find how to use them. Could the basics be added to the help property list?

Set psWatermark to "pricemaintenance.png"
Set piWatermarkTransparency to 20
Set peWatermarkAlignment to (xtpReportWatermarkCenter + xtpReportWatermarkStretch)