Currently only works with ODF (although signature lines are roundtripped in OOXML). Shouldn't be too hard to have this also for OOXML. We need to write the graphics as base64 encoded emf graphics to the signature.
Samuel Mehrbrodt committed a patch related to this issue. It has been pushed to "master": http://cgit.freedesktop.org/libreoffice/core/commit/?id=7bafb7ca8ef9467f5c55766d2a38ba0d0a60837c tdf#117901 Write signature line images as emf to ooxml It will be available in 6.2.0. The patch should be included in the daily builds available at http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: http://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.
Samuel Mehrbrodt committed a patch related to this issue. It has been pushed to "libreoffice-6-1": http://cgit.freedesktop.org/libreoffice/core/commit/?id=34c1d80d91b62afa74d0566d88b7f4fbd0dcb433&h=libreoffice-6-1 tdf#117901 Write signature line images as emf to ooxml It will be available in 6.1.0.2. The patch should be included in the daily builds available at http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: http://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.
Closing this, related problem is bug 118567.