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 CellsDocument = Document.Load(Of CellsDocument)(Utilities.MapSourceFilePath(FilePath))
    Using watermark As New ImageWatermark("D:\logo.gif")
        watermark.HorizontalAlignment = HorizontalAlignment.Center
        watermark.VerticalAlignment = VerticalAlignment.Center
        watermark.RotateAngle = 90
        watermark.SizingType = SizingType.ScaleToParentDimensions
        watermark.ScaleFactor = 0.5
        'set background width
        'set background height
        doc.Worksheets(0).AddWatermarkAsBackground(watermark, doc.Worksheets(0).ContentAreaWidthPx, doc.Worksheets(0).ContentAreaHeightPx)
    End Using

    doc.Save()
End Using