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 (Document doc = Document.Load(Utilities.MapSourceFilePath (XlsFilePath)))
{
    Font font = new Font("Calibri", 12);
    TextWatermark watermark = new TextWatermark("Test watermark", font);
    watermark.HorizontalAlignment = HorizontalAlignment.Right;
    watermark.VerticalAlignment = VerticalAlignment.Bottom;

    // Set absolute margins. Values are measured in document units.
    watermark.Margins.Right = 10;
    watermark.Margins.Bottom = 5;

    doc.AddWatermark(watermark);
    doc.Save();
}