Hi avalon86 The minimum to change a signed pdf without invalidating the signature, is to use an incremental save. use the SaveToFileInc function for example see : https://www.gdpicture.com/guides/gdpicture/Overview.html#GdPicture.NET.14~GdPicture14.GdPicturePDF~SaveToFileInc.html Hope this help Jea...