1. GroupDocs Documentation
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    3. GroupDocs.Watermark Product Family
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    5. GroupDocs.Watermark for .NET
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    7. Developer guide
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    9. Advanced usage
    10. /
    11. Adding watermarks
    12. /
    13. Text watermarks

    Adding text watermarks

    The following code snippet shows how to add text watermark to a document. If the document consists of multiple parts (pages, worksheets, slides, frames, etc.), the watermark will be added to each of them.

    AdvancedUsage.AddingTextWatermarks.AddTextWatermark

    // Specify an absolute or relative path to your image. Ex: @"C:\Docs\image.png"
using (Watermarker watermarker = new Watermarker("image.png"))
{
    // Initialize the font to be used for watermark
    Font font = new Font("Arial", 19, FontStyle.Bold | FontStyle.Italic);

    // Create the watermark object
    TextWatermark watermark = new TextWatermark("Test watermark", font);

    // Set watermark properties
    watermark.ForegroundColor = Color.Red;
    watermark.BackgroundColor = Color.Blue;
    watermark.TextAlignment = TextAlignment.Right;
    watermark.Opacity = 0.5;

    // Add watermark
    watermarker.Add(watermark);
    watermarker.Save("image.png");
}

    Sizing and positioning of watermark

    Absolute watermark positioning

    Using GroupDocs.Watermark, you can also add watermark to some absolute position in the document. Following example shows how to add a text watermark with absolute positioning using properties X, Y, Width and Height. The values of all properties for absolute sizing and positioning are measured in default document units.

    AdvancedUsage.AddingTextWatermarks.AddWatermarkToAbsolutePosition

    // Specify an absolute or relative path to your image. Ex: @"C:\Docs\image.png"
using (Watermarker watermarker = new Watermarker("image.png"))
{
    Font font = new Font("Times New Roman", 8);
    TextWatermark watermark = new TextWatermark("Test watermark", font);

    // Set watermark coordinates
    watermark.X = 10;
    watermark.Y = 20;

    // Set watermark size
    watermark.Width = 100;
    watermark.Height = 40;

    watermarker.Add(watermark);
    watermarker.Save("image.png");
}
    Warning
    Note that the origin of coordinates may be different for different document types (relative positioning doesn’t have these specifics and can be used as a unified positioning approach).

    Following are the origin of the coordinates for different formats of the documents.

    Document FormatUnit of MeasureOrigin of Coordinates
    PDFPointLeft bottom corner of page
    WordProcessingPointLeft top corner of page 
    SpreadsheetPointLeft top corner of worksheet 
    PresentationPointLeft top corner of slide 
    ImagePixelLeft top corner of image (frame) 
    DiagramPointLeft top corner of page

    Relative watermark positioning 

    Instead of exact coordinates, you can also use parent relative alignment. Furthermore, you can also set offset from parent’s borders by using Margins property as shown in below example. Following example shows how to align the watermark vertically and horizontally.

    AdvancedUsage.AddingTextWatermarks.AddWatermarkToRelativePosition

    // Specify an absolute or relative path to your image. Ex: @"C:\Docs\image.png"
using (Watermarker watermarker = new Watermarker("image.png"))
{
    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;

    watermarker.Add(watermark);
    watermarker.Save("image.png");
}
    Warning
    Excel worksheets don’t have explicit borders, therefore, the most right bottom non-empty cell is used to determine working area size.

    Using the MarginType property

    In the example above, absolute margin values are used. This means that margins are measured in document units. But you can set relative margins for a watermark as well (as shown in below example).

    AdvancedUsage.AddingTextWatermarks.AddWatermarkWithMarginType

    // Specify an absolute or relative path to your image. Ex: @"C:\Docs\image.png"
using (Watermarker watermarker = new Watermarker("image.png"))
{
    Font font = new Font("Calibri", 12);
    TextWatermark watermark = new TextWatermark("Test watermark", font);
    watermark.HorizontalAlignment = HorizontalAlignment.Right;
    watermark.VerticalAlignment = VerticalAlignment.Bottom;

    // Set relative margins. Margin value will be interpreted as a portion
    // of appropriate parent dimension. If this type is chosen, margin value
    // must be between 0.0 and 1.0.
    watermark.Margins.MarginType = MarginType.RelativeToParentDimensions;
    watermark.Margins.Right = 0.1;
    watermark.Margins.Bottom = 0.2;

    watermarker.Add(watermark);
    watermarker.Save("image.png");
}

    Size types

    In most cases, to add a good-looking watermark, you should consider the size of the page/slide/frame on which it will be placed. The SizingType and ScaleFactor properties can be used to scale the watermark depending on the parent size.

    AdvancedUsage.AddingTextWatermarks.AddWatermarkWithSizeType

    // Specify an absolute or relative path to your image. Ex: @"C:\Docs\image.png"
using (Watermarker watermarker = new Watermarker("image.png"))
{
    Font font = new Font("Calibri", 12);
    TextWatermark watermark = new TextWatermark("This is a test watermark", font);

    // Set sizing type
    watermark.SizingType = SizingType.ScaleToParentDimensions;

    // Set watermark scale
    watermark.ScaleFactor = 0.5;

    watermarker.Add(watermark);
    watermarker.Save("image.png");
}
    Note
    Using of relative size and positioning is the simplest way to add watermark to a document of any type.

    Watermark rotation

    GroupDocs.Watermark API also supports rotation of the watermark. You can use RotateAngle property to define watermark rotation angle in degrees. A positive value means clockwise rotation.

    AdvancedUsage.AddingTextWatermarks.AddTextWatermarkWithRotationAngle

    // Specify an absolute or relative path to your document. Ex: @"C:\Docs\test.docx"
using (Watermarker watermarker = new Watermarker("test.docx"))
{
    Font font = new Font("Calibri", 8);
    TextWatermark watermark = new TextWatermark("Test watermark", font);
    watermark.HorizontalAlignment = HorizontalAlignment.Right;
    watermark.VerticalAlignment = VerticalAlignment.Top;
    watermark.SizingType = SizingType.ScaleToParentDimensions;
    watermark.ScaleFactor = 0.5;

    // Set rotation angle
    watermark.RotateAngle = 45;

    watermarker.Add(watermark);
    watermarker.Save("test.docx");
}

    If rotation angle is set, it is assumed that watermark size is equal to axis-aligned bounding box size. The following picture illustrates what is the watermark bounding box and how it is used for sizing and positioning. The picture shows a result of execution of the above code snippet. The actual watermark bounds are colored in blue and the bounding box is colored in red. As you can see, the bounding box size is used to calculate watermark relative size.

    adding-text-watermarks

    Considering parent margins

    For most document formats you can set page margins when working with a document. By default, GroupDocs.Watermark ignores document margins and uses maximum available space for watermarking as shown in below image.

    adding-text-watermarks_1

    As you can see, the watermark goes beyond page margins. To change this behavior, set ConsiderParentMargins property to true (as shown in below example).

    AdvancedUsage.AddingTextWatermarks.AddWatermarkWithParentMargin

    // Specify an absolute or relative path to your document. Ex: @"C:\Docs\input.vsdx"
using (Watermarker watermarker = new Watermarker("input.vsdx"))
{
    TextWatermark watermark = new TextWatermark("Test watermark", new Font("Arial", 42));
    watermark.HorizontalAlignment = HorizontalAlignment.Right;
    watermark.VerticalAlignment = VerticalAlignment.Top;
    watermark.SizingType = SizingType.ScaleToParentDimensions;
    watermark.ScaleFactor = 1;
    watermark.RotateAngle = 45;
    watermark.ForegroundColor = Color.Red;
    watermark.BackgroundColor = Color.Aqua;

    // Add watermark considering parent margins
    watermark.ConsiderParentMargins = true;

    watermarker.Add(watermark);
    watermarker.Save("input.vsdx");
}

    Now, the watermark is aligned with respect to page margins.

    adding-text-watermarks_2

    Watermark in documents of different types

    Watermarks in documents of different types are represented by different objects. Some of these objects do not support some watermark properties. For example, the background color can not be set for WordArt object which is used as text watermark in a Word document. The full list of supported properties for all document types is available at Features Overview.

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