Watermarking

VB C#

using IronPdf;

// Stamps a Watermark onto a new or existing PDF
var renderer = new ChromePdfRenderer();

var pdf = renderer.RenderUrlAsPdf("https://www.nuget.org/packages/IronPdf");
pdf.ApplyWatermark("<h2 style='color:red'>SAMPLE</h2>", 30, IronPdf.Editing.VerticalAlignment.Middle, IronPdf.Editing.HorizontalAlignment.Center);
pdf.SaveAs("watermarked.pdf");

Imports IronPdf

' Stamps a Watermark onto a new or existing PDF
Private renderer = New ChromePdfRenderer()

Private pdf = renderer.RenderUrlAsPdf("https://www.nuget.org/packages/IronPdf")
pdf.ApplyWatermark("<h2 style='color:red'>SAMPLE</h2>", 30, IronPdf.Editing.VerticalAlignment.Middle, IronPdf.Editing.HorizontalAlignment.Center)
pdf.SaveAs("watermarked.pdf")

Install-Package IronPdf

Watermarking

IronPDF provides methods to 'watermark' PDF documents with HTML.

Using the ApplyWatermark method, developers can add an HTML-based watermark to a PDF file. As shown in the example above, the HTML code for the watermark goes as the first argument to the method. Additional arguments to ApplyWatermark control the opacity, rotation, and alignment of the watermark.

Use the ApplyWatermark method for a quick way to overlay an HTML watermark on a PDF. For example, use ApplyWatermark to:

Add HTML (text or image) watermarks to PDFs
Apply the watermark across the pages of the PDF
Set the opacity of the watermark
Adjust the rotation and alignment of the watermark

How to Add Watermarks to PDF Files in C#

Download and install the IronPDF library from NuGet.
Create a new PdfDocument or use an existing PdfDocument file.
Call the ApplyWatermark method to add watermarks to the PDF.
Export the PDF file by calling SaveAs.

Example C# Code to Apply a Watermark Using IronPDF

Ensure you have installed the IronPDF library in your project. You can find more detailed instructions on the IronPDF NuGet package page.

Explanation of the Code:

We start by importing the IronPdf library, which provides all necessary classes and methods for PDF manipulation.
A PDF document is created or loaded using PdfDocument.FromFile, specifying the file path of the existing PDF.
HTML content is defined for the watermark. In this case, the watermark displays "Confidential" with specific styling.
The ApplyWatermark method is used to overlay the watermark on the PDF. Its arguments allow for customization:
- The first argument is the HTML content of the watermark.
- opacity: Determines the transparency of the watermark.
- The vertical and horizontal alignment arguments position the watermark on the page.
Finally, the SaveAs method exports the modified PDF to a new file.

In conclusion, the IronPDF ApplyWatermark method allows for straightforward watermarking of PDF documents using HTML. This approach is flexible, accommodating various customization needs for positioning, styling, and opacity of watermarks.

Explore Custom Watermarking with IronPDF

View on GitHub

Code

https://github.com/iron-software/IronPdf.Examples/tree/main/examples/pdf-watermarking

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