// Install IronPdf with Nuget:  PM> Install-Package IronPdf
using IronPdf;

// Stamps a watermark onto a new or existing PDF
IronPdf.HtmlToPdf Renderer = new IronPdf.HtmlToPdf();
var pdf =  Renderer.RenderUrlAsPdf("https://www.nuget.org/packages/IronPdf");
pdf.WatermarkAllPages("<h2 style='color:red'>SAMPLE</h2>", PdfDocument.WaterMarkLocation.MiddleCenter, 50, -45, "https://www.nuget.org/packages/IronPdf");
pdf.SaveAs(@"C:\Path\To\Watermarked.pdf");

' Install IronPdf with Nuget:  PM> Install-Package IronPdf
Imports IronPdf

' Stamps a watermark onto a new or existing PDF
Private Renderer As New IronPdf.HtmlToPdf()
Private pdf = Renderer.RenderUrlAsPdf("https://www.nuget.org/packages/IronPdf")
pdf.WatermarkAllPages("<h2 style='color:red'>SAMPLE</h2>", PdfDocument.WaterMarkLocation.MiddleCenter, 50, -45, "https://www.nuget.org/packages/IronPdf")
pdf.SaveAs("C:\Path\To\Watermarked.pdf")