Cacher is the code snippet organizer for pro developers

' For complete examples and data files, please go to https://github.com/groupdocs-watermark/GroupDocs.Watermark-for-.NET
Using doc As SlidesDocument = Document.Load(Of SlidesDocument)("D:\test.pptx")
    Dim watermark As New TextWatermark("Test watermark", New Font("Segoe UI", 19))

    Dim effects As New SlidesTextEffects()
    effects.LineFormat.Enabled = True
    effects.LineFormat.Color = Color.Red
    effects.LineFormat.DashStyle = OfficeDashStyle.DashDotDot
    effects.LineFormat.LineStyle = OfficeLineStyle.Triple
    effects.LineFormat.Weight = 1
    doc.AddTextWatermark(watermark, effects)
    doc.Save()
End Using