' 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))
Dim watermark As New TextWatermark("Test watermark", New Font("Segoe UI", 19))
Dim shapeSettings As New CellsShapeSettings()
' Set the shape name
shapeSettings.Name = "Shape 1"
' Set the descriptive (alternative) text that will be associated with the shape
shapeSettings.AlternativeText = "Test watermark"
' Editing of the shape in Excel is forbidden
shapeSettings.IsLocked = True
doc.AddWatermark(watermark, shapeSettings)
doc.Save()
End Using