Add Watermarks to PDF Documents Using C#

Optimize document workflows by programmatically adding watermarks to PDF files with 'Wordize for .NET'. Whether protecting proprietary PDF files or branding official reports, our solution applies professional watermarks with precise positioning across all PDF pages. The C# API enables creation of text/image watermarks with extensive customization, saving manual editing time while ensuring fast, professional results for PDF documents.

Key Features

Customizable text watermarks with font controls and transparency
Image watermark support for PNG, JPEG and other formats
Positioning via coordinates or predefined locations (center, diagonal)
Rotation angle, transparency, and layering adjustments

Use Cases

Confidential Documents: "Confidential" or "Not for Distribution" stamps
Draft Materials: "Draft" or "Under Review" markings
Corporate Docs: Brand reinforcement with company logos
Licensed Content: Copyright notices and IP protection

Wordize provides developers powerful tools for automating PDF watermarking in C#. With flexible settings, adapt watermarks to exact requirements. By integrating Wordize into .NET projects, developers create robust solutions for document branding, security, and workflow management.

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Text of the watermark

Select the target format from the list

 
using Wordize.Watermarking;

Watermarker.SetText("Input.pdf", "Output.pdf", "Text");

										using Wordize.Watermarking;

Watermarker.SetText("Input.pdf", "Output.pdf", "Text");

										using Wordize.Watermarking;
using Wordize.Saving;

var imageStreams = Watermarker.SetWatermarkToImages("Input.pdf", new ImageSaveOptions(SaveFormat.Pdf), "Text");

foreach (var (stream, page) in imageStreams.Select((s, i) => (s, i)))
{
    using var _ = stream;
    stream.Position = 0;
    
    using var file = File.Create($"Output_{page + 1}.pdf");
    stream.CopyTo(file);
}

using Wordize.Watermarking;

Watermarker.SetImage("Input.pdf", "Output.pdf", "Watermark.jpg");

										using Wordize.Watermarking;

Watermarker.SetImage("Input.pdf", "Output.pdf", "Watermark.jpg");

										using Wordize.Watermarking;
using Wordize.Saving;

byte[] watermarkImageBytes = File.ReadAllBytes("Watermark.jpg");
var imageStreams = Watermarker.SetWatermarkToImages("Input.pdf", new ImageSaveOptions(SaveFormat.Pdf), watermarkImageBytes);

foreach (var (stream, page) in imageStreams.Select((s, i) => (s, i)))
{
    using var _ = stream;
    stream.Position = 0;
    
    using var file = File.Create($"Output_{page + 1}.pdf");
    stream.CopyTo(file);
}

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How to Add Watermarks to PDF Files in C#

Install Wordize for .NET
Add library reference (import package) to C# project
Create text/image watermark in PDF with required parameters