Discover the Best Alternatives for QuestPDF Watermarking in .NET

IronPDF makes use of HTML string and CSS styling to add fully customizable watermarks to your PDF documents. The watermark tool can take any HTML string, even if it contains assets such as images and CSS styling, and apply it to the PDF file as a watermark.

using IronPdf;

class Program
{
    static void Main()
    {
        // Load an existing PDF document.
        PdfDocument pdf = PdfDocument.FromFile("existing.pdf");

        // Define the watermark using HTML and CSS.
        string watermark = "<img src='https://ironsoftware.com/img/products/ironpdf-logo-text-dotnet.svg'><h1 style='color:red;'>CONFIDENTIAL</h1>";

        // Apply the watermark with specified rotation and opacity.
        pdf.ApplyWatermark(watermark, rotation: 45, opacity: 80);

        // Save the watermarked document.
        pdf.SaveAs("watermarked.pdf");
    }
}

using IronPdf;

class Program
{
    static void Main()
    {
        // Load an existing PDF document.
        PdfDocument pdf = PdfDocument.FromFile("existing.pdf");

        // Define the watermark using HTML and CSS.
        string watermark = "<img src='https://ironsoftware.com/img/products/ironpdf-logo-text-dotnet.svg'><h1 style='color:red;'>CONFIDENTIAL</h1>";

        // Apply the watermark with specified rotation and opacity.
        pdf.ApplyWatermark(watermark, rotation: 45, opacity: 80);

        // Save the watermarked document.
        pdf.SaveAs("watermarked.pdf");
    }
}

Output PDF File

As you can see, we have created a new string variable containing our watermark content. This is made up of an HTML string with a header and image. When we use the ApplyWatermark method, we are able to set a customized rotation and opacity.

If you want to see more advanced examples and other features IronPDF has to offer, be sure to check out the How-To Guides!

QuestPDF has a different approach to apply watermarks to PDF files. With QuestPDF, this is done through watermark slots (on the background and foreground) which are used to add watermark content to a specific page or all pages of the PDF.

using QuestPDF.Fluent;
using QuestPDF.Helpers;
using QuestPDF.Infrastructure;

public class WatermarkExample
{
    public static void Main()
    {
        // Set the license type to Community for QuestPDF.
        QuestPDF.Settings.License = LicenseType.Community;

        // Create a PDF document with a defined structure.
        Document.Create(container =>
        {
            container.Page(page =>
            {
                page.Margin(50);

                // Add a foreground watermark.
                page.Foreground().Element(watermark =>
                {
                    watermark.Text("DRAFT")
                        .FontSize(40)
                        .FontColor(Colors.Red.Medium)
                        .AlignLeft();
                });

                // Add the main content of the page.
                page.Content().Element(ComposeContent);
            });
        })
        .GeneratePdf("watermarked_document.pdf");
    }

    private static IContainer ComposeContent(IContainer container)
    {
        // Define the layout and content of the PDF.
        container.Column(column =>
        {
            column.Spacing(10);
            column.Item().Text("This is the main content of the PDF.");
            column.Item().Text("Add more content as needed.");
        });

        return container; // Return the container to maintain method signature.
    }
}

using QuestPDF.Fluent;
using QuestPDF.Helpers;
using QuestPDF.Infrastructure;

public class WatermarkExample
{
    public static void Main()
    {
        // Set the license type to Community for QuestPDF.
        QuestPDF.Settings.License = LicenseType.Community;

        // Create a PDF document with a defined structure.
        Document.Create(container =>
        {
            container.Page(page =>
            {
                page.Margin(50);

                // Add a foreground watermark.
                page.Foreground().Element(watermark =>
                {
                    watermark.Text("DRAFT")
                        .FontSize(40)
                        .FontColor(Colors.Red.Medium)
                        .AlignLeft();
                });

                // Add the main content of the page.
                page.Content().Element(ComposeContent);
            });
        })
        .GeneratePdf("watermarked_document.pdf");
    }

    private static IContainer ComposeContent(IContainer container)
    {
        // Define the layout and content of the PDF.
        container.Column(column =>
        {
            column.Spacing(10);
            column.Item().Text("This is the main content of the PDF.");
            column.Item().Text("Add more content as needed.");
        });

        return container; // Return the container to maintain method signature.
    }
}

Output PDF Document

In the Main method, we start by creating a document with a page that has a 50-unit margin. We then create the watermark we want to use, which is the simple text "DRAFT" in red, styled with a font size of 40 and aligned to the left. This approach to applying watermarks to PDF documents is more rigid and complex in setup compared to IronPDF's streamlined approach. With QuestPDF, you may have less control over the appearance and location of the watermark.