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 ApplyStamp 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 ApplyStamp control the rotation, opacity, and position of the watermark.

Utilize the ApplyStamp method in lieu of the ApplyWatermark method for more granular control over watermark placement. For example, use ApplyStamp to:

Add Text, Image, or HTML watermarks to PDFs
Apply the same watermark to every page of the PDF
Apply different watermarks to specific PDF pages
Adjust the placement of watermarks in front or behind page copy
Adjust the opacity, rotation, and alignment of watermarks with more precision

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 ApplyStamp 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 ApplyStamp method is used to overlay the watermark on the PDF. This method allows for detailed customization:
- rotationDegrees: Specifies the rotation, in degrees, of the watermark.
- left and top: Dictate the X and Y position of the watermark, measured from the top-left corner.
- opacity: Determines the transparency of the watermark.
- pageRange: Specifies which pages should receive the watermark, allowing for diverse placement strategies.
Finally, the SaveAs method exports the modified PDF to a new file.

In conclusion, the IronPDF ApplyStamp method allows for precise control over watermarking PDF documents using HTML. This approach is flexible, accommodating various customization needs for positioning, styling, and applying watermarks to specified pages.

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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