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Published November 30, 2023

How to Add PDF Stamper in C#

Stamping text and images on a PDF involves overlaying additional content onto an existing PDF document. This content, often called a "stamp," can be text, images, or a combination. Typically, users add information, labels, watermarks, or annotations to a PDF using stamps.

IronPDF provides a user-friendly and versatile solution for customizing PDF content to meet various needs. The Stamper Abstract Class is a key component in IronPDF's stamping methods, for a range of specialized stamper classes, each designed for specific purposes.

  1. TextStamper: The TextStamper is your solution for adding descriptive text to PDFs. Whether you're enhancing an existing document, placing text on the same page, or incorporating details from other PDF documents, this stamper allows you to customize your files with file descriptions and information.
  2. ImageStamper: The ImageStamper is the go-to tool for placing images within your PDFs. Whether it's a logo for file description, an illustration for an existing document, or a visual element for the same page or other PDF document, this stamper ensures seamless integration of images.
  3. HtmlStamper: The HtmlStamper takes customization to the next level, allowing you to stamp HTML content onto your PDFs. This includes creating dynamic elements like interactive content, descriptions, and file specifications, providing flexibility beyond traditional PDF customization.
  4. BarcodeStamper to stamp Barcodes: The BarcodeStamper simplifies the process of adding barcodes to your PDFs. Whether it's for tracking purposes in a signed document, temporary file, or file attachment, this stamper ensures efficient integration of barcodes into your PDFs.
  5. BarcodeStamper to stamp QR Codes: The BarcodeStamper specializes in placing QR codes as well on your PDFs. Perfect for creating interactive content or file attachments, this stamper allows you to embed QR codes on the same page or other PDF documents, ensuring easy access to additional information.

These specialized stamper classes facilitate users to easily enhance PDF documents with various elements, from basic text to intricate HTML designs and dynamic barcodes. In this article, we'll explore the functionalities of three main stampers: TextStamper, ImageStamper, and HTMLStamper. HTMLStamper is particularly powerful because it can make use of all HTML features, coupled with CSS styling, adding an extra layer of versatility to the stamping process.

How to Stamp Text & Image on PDFs

  1. Download the C# library to stamp text and images.
  2. Create and configure the desired stamper class.
  3. Use the 'ApplyStamp' method to apply the stamp to the PDF.
  4. Apply multiple stamps using the 'ApplyMultipleStamps' method.
  5. Specify particular pages to apply the stamps to.

Configuring and Applying Text Stamps in PDFs

First, create an object from the TextStamper class to support text stamping in PDFs. The object of this class contains all the configurations to specify how our text stamper is presented. Pass the textStamper object to the 'ApplyStamp' method. The Text property defines the content to be displayed on the PDF.

Furthermore, we can specify font family, font styling, as well as the location of the Stamp. This customization extends to interactive elements, file descriptions, and existing content on the same or other PDFs. Then, export the PDF with the actual file name.

On completing the configurations, export the output PDF file with the designated file name, encapsulating all settings and providing a professional touch to your documents.

using IronPdf;
using IronPdf.Editing;

ChromePdfRenderer renderer = new ChromePdfRenderer();

PdfDocument pdf = renderer.RenderHtmlAsPdf("<h1>Example HTML Document!</h1>");

// Create text stamper
TextStamper textStamper = new TextStamper()
{
    Text = "Text Stamper!",
    FontFamily = "Bungee Spice",
    UseGoogleFont = true,
    FontSize = 30,
    IsBold = true,
    IsItalic = true,
    VerticalAlignment = VerticalAlignment.Top,
};

// Stamp the text stamper
pdf.ApplyStamp(textStamper);

pdf.SaveAs("stampText.pdf");

using IronPdf;
using IronPdf.Editing;

ChromePdfRenderer renderer = new ChromePdfRenderer();

PdfDocument pdf = renderer.RenderHtmlAsPdf("<h1>Example HTML Document!</h1>");

// Create text stamper
TextStamper textStamper = new TextStamper()
{
    Text = "Text Stamper!",
    FontFamily = "Bungee Spice",
    UseGoogleFont = true,
    FontSize = 30,
    IsBold = true,
    IsItalic = true,
    VerticalAlignment = VerticalAlignment.Top,
};

// Stamp the text stamper
pdf.ApplyStamp(textStamper);

pdf.SaveAs("stampText.pdf");

Imports IronPdf
Imports IronPdf.Editing

Private renderer As New ChromePdfRenderer()

Private pdf As PdfDocument = renderer.RenderHtmlAsPdf("<h1>Example HTML Document!</h1>")

' Create text stamper
Private textStamper As New TextStamper() With {
	.Text = "Text Stamper!",
	.FontFamily = "Bungee Spice",
	.UseGoogleFont = True,
	.FontSize = 30,
	.IsBold = True,
	.IsItalic = True,
	.VerticalAlignment = VerticalAlignment.Top
}

' Stamp the text stamper
pdf.ApplyStamp(textStamper)

pdf.SaveAs("stampText.pdf")
VB   C#

Configuring and Applying Image Stamps in PDF

Similar to the text stamper, we first create an object from the ImageStamper class and then use the ApplyStamp method to apply the image to the document. This method's second parameter also accommodates a page index, enabling the stamp application to single or multiple pages. In this specific instance, we are instructing the system to apply the image as a stamp, particularly on the first page of the PDF.

All page indexes follow zero-based indexing.

using IronPdf;
using IronPdf.Editing;

ChromePdfRenderer renderer = new ChromePdfRenderer();

PdfDocument pdf = renderer.RenderHtmlAsPdf("<h1>Example HTML Document!</h1>");

// Create image stamper
ImageStamper imageStamper = new ImageStamper(new Uri("https://ironpdf.com/img/svgs/iron-pdf-logo.svg"))
{
    VerticalAlignment = VerticalAlignment.Top,
};

// Stamp the image stamper
pdf.ApplyStamp(imageStamper, 0);

pdf.SaveAs("stampImage.pdf");
using IronPdf;
using IronPdf.Editing;

ChromePdfRenderer renderer = new ChromePdfRenderer();

PdfDocument pdf = renderer.RenderHtmlAsPdf("<h1>Example HTML Document!</h1>");

// Create image stamper
ImageStamper imageStamper = new ImageStamper(new Uri("https://ironpdf.com/img/svgs/iron-pdf-logo.svg"))
{
    VerticalAlignment = VerticalAlignment.Top,
};

// Stamp the image stamper
pdf.ApplyStamp(imageStamper, 0);

pdf.SaveAs("stampImage.pdf");
Imports IronPdf
Imports IronPdf.Editing

Private renderer As New ChromePdfRenderer()

Private pdf As PdfDocument = renderer.RenderHtmlAsPdf("<h1>Example HTML Document!</h1>")

' Create image stamper
Private imageStamper As New ImageStamper(New Uri("https://ironpdf.com/img/svgs/iron-pdf-logo.svg")) With {.VerticalAlignment = VerticalAlignment.Top}

' Stamp the image stamper
pdf.ApplyStamp(imageStamper, 0)

pdf.SaveAs("stampImage.pdf")
VB   C#

Apply Multiple Stamps

To add multiple stamps to a document, use the 'ApplyMultipleStamps' method in IronPDF by passing an array of stampers. It lets you add various elements, like text, images, or labels, all in one go. We create two text stampers with different text and alignments in this example. The 'pdf.ApplyMultipleStamps' applies both stamps to the PDF, and the final document is saved as 'multipleStamps.pdf.' This method streamlines the process of adding various stamps, providing a convenient way to enhance your PDF with multiple elements, whether on the same page, another PDF, or even a blank page.

using IronPdf;
using IronPdf.Editing;

ChromePdfRenderer renderer = new ChromePdfRenderer();

PdfDocument pdf = renderer.RenderHtmlAsPdf("<h1>Example HTML Document!</h1>");

// Create two text stampers
TextStamper stamper1 = new TextStamper()
{
    Text = "Text stamp 1",
    VerticalAlignment = VerticalAlignment.Top,
    HorizontalAlignment = HorizontalAlignment.Left,
};

TextStamper stamper2 = new TextStamper()
{
    Text = "Text stamp 2",
    VerticalAlignment = VerticalAlignment.Top,
    HorizontalAlignment = HorizontalAlignment.Right,
};

Stamper[] stampersToApply = { stamper1, stamper2 };

// Apply multiple stamps
pdf.ApplyMultipleStamps(stampersToApply);

pdf.SaveAs("multipleStamps.pdf");

using IronPdf;
using IronPdf.Editing;

ChromePdfRenderer renderer = new ChromePdfRenderer();

PdfDocument pdf = renderer.RenderHtmlAsPdf("<h1>Example HTML Document!</h1>");

// Create two text stampers
TextStamper stamper1 = new TextStamper()
{
    Text = "Text stamp 1",
    VerticalAlignment = VerticalAlignment.Top,
    HorizontalAlignment = HorizontalAlignment.Left,
};

TextStamper stamper2 = new TextStamper()
{
    Text = "Text stamp 2",
    VerticalAlignment = VerticalAlignment.Top,
    HorizontalAlignment = HorizontalAlignment.Right,
};

Stamper[] stampersToApply = { stamper1, stamper2 };

// Apply multiple stamps
pdf.ApplyMultipleStamps(stampersToApply);

pdf.SaveAs("multipleStamps.pdf");

Imports IronPdf
Imports IronPdf.Editing

Private renderer As New ChromePdfRenderer()

Private pdf As PdfDocument = renderer.RenderHtmlAsPdf("<h1>Example HTML Document!</h1>")

' Create two text stampers
Private stamper1 As New TextStamper() With {
	.Text = "Text stamp 1",
	.VerticalAlignment = VerticalAlignment.Top,
	.HorizontalAlignment = HorizontalAlignment.Left
}

Private stamper2 As New TextStamper() With {
	.Text = "Text stamp 2",
	.VerticalAlignment = VerticalAlignment.Top,
	.HorizontalAlignment = HorizontalAlignment.Right
}

Private stampersToApply() As Stamper = { stamper1, stamper2 }

' Apply multiple stamps
pdf.ApplyMultipleStamps(stampersToApply)

pdf.SaveAs("multipleStamps.pdf")
VB   C#

Specifying Stamp Location on PDF Document

To define the placement of the Stamp, we utilize a 3x3 grid with three horizontal columns and three vertical rows. You have choices for horizontal alignment left, center, and right, and vertical alignment: top, middle, and bottom. You can adjust horizontal and vertical offsets for added precision for each position. Please refer to the image below for a visual representation of this concept.

pdf-stamper-charp-positioning

  • HorizontalAlignment: The horizontal alignment of the Stamp relative to the page.
  • VerticalAlignment: The vertical alignment of the stamp relative to the page.
  • HorizontalOffset: The horizontal offset. The default value is 0, and the default unit is IronPdf.Editing.MeasurementUnit.Percentage. Positive values indicate an offset to the right direction, while negative values indicate an offset to the left direction.
  • VerticalOffset: The vertical offset. The default value is 0, and the default unit is IronPdf.Editing.MeasurementUnit.Percentage. Positive values indicate an offset in the downward direction, while negative values indicate an offset in the upward direction.

To specify the HorizontalOffset and VerticalOffset properties, we instantiate the Length class. The default measurement unit for Length is a percentage, but it can also use measurement units such as inches, millimeters, centimeters, pixels, and points.


using IronPdf.Editing;

// Create text stamper
ImageStamper imageStamper = new ImageStamper(new Uri("https://ironpdf.com/img/svgs/iron-pdf-logo.svg"))
{
    HorizontalAlignment = HorizontalAlignment.Center,
    VerticalAlignment = VerticalAlignment.Top,

    // Specify offsets
    HorizontalOffset = new Length(10),
    VerticalOffset = new Length(10),
};


using IronPdf.Editing;

// Create text stamper
ImageStamper imageStamper = new ImageStamper(new Uri("https://ironpdf.com/img/svgs/iron-pdf-logo.svg"))
{
    HorizontalAlignment = HorizontalAlignment.Center,
    VerticalAlignment = VerticalAlignment.Top,

    // Specify offsets
    HorizontalOffset = new Length(10),
    VerticalOffset = new Length(10),
};

Imports IronPdf.Editing

' Create text stamper
Private imageStamper As New ImageStamper(New Uri("https://ironpdf.com/img/svgs/iron-pdf-logo.svg")) With {
	.HorizontalAlignment = HorizontalAlignment.Center,
	.VerticalAlignment = VerticalAlignment.Top,
	.HorizontalOffset = New Length(10),
	.VerticalOffset = New Length(10)
}
VB   C#

Configuring and Applying HTML Stamps in PDF

There is another stamper class that we can use to stamp both text and images. The HtmlStamper class can render HTML designs with CSS styling and stamp them onto the PDF document. The InnerHtmlBaseUrl property is used to specify the base URL for the HTML string assets, such as CSS and image files.

The HTMLStamper class is applied to the PDF. This stamper object includes an image and text, and you can define these in the HTML fragment which is to be stamped onto your PDF. All external references to JavaScript, CSS, and image files will be relative to IronPdf.Editing.Stamper.InnerHtmlBaseUrl. This code allows you to customize the PDF according to specific file specification mentioned in the HTML content. Lastly, the modified PDF is saved with the filename 'stampHtml.pdf.'


using IronPdf;
using IronPdf.Editing;

ChromePdfRenderer renderer = new ChromePdfRenderer();

PdfDocument pdf = renderer.RenderHtmlAsPdf("<h1>Example HTML Document!</h1>");

// Create HTML stamper
HtmlStamper htmlStamper = new HtmlStamper()
{
    Html = @"<img src='https://ironpdf.com/img/svgs/iron-pdf-logo.svg'>
    <h1>Iron Software</h1>",
    VerticalAlignment = VerticalAlignment.Top,
};

// Stamp the HTML stamper
pdf.ApplyStamp(htmlStamper);

pdf.SaveAs("stampHtml.pdf");


using IronPdf;
using IronPdf.Editing;

ChromePdfRenderer renderer = new ChromePdfRenderer();

PdfDocument pdf = renderer.RenderHtmlAsPdf("<h1>Example HTML Document!</h1>");

// Create HTML stamper
HtmlStamper htmlStamper = new HtmlStamper()
{
    Html = @"<img src='https://ironpdf.com/img/svgs/iron-pdf-logo.svg'>
    <h1>Iron Software</h1>",
    VerticalAlignment = VerticalAlignment.Top,
};

// Stamp the HTML stamper
pdf.ApplyStamp(htmlStamper);

pdf.SaveAs("stampHtml.pdf");

Imports IronPdf
Imports IronPdf.Editing

Private renderer As New ChromePdfRenderer()

Private pdf As PdfDocument = renderer.RenderHtmlAsPdf("<h1>Example HTML Document!</h1>")

' Create HTML stamper
Private htmlStamper As New HtmlStamper() With {
	.Html = "<img src='https://ironpdf.com/img/svgs/iron-pdf-logo.svg'>
    <h1>Iron Software</h1>",
	.VerticalAlignment = VerticalAlignment.Top
}

' Stamp the HTML stamper
pdf.ApplyStamp(htmlStamper)

pdf.SaveAs("stampHtml.pdf")
VB   C#

HTML Stamper Options

In addition to the options mentioned and explained above, below are more available to the stamper classes.

  • Opacity: Allows the Stamp to be transparent. 0 is entirely invisible, and 100 is fully opaque.
  • Rotation: Rotates the Stamp clockwise from 0 to 360 degrees as specified.
  • MaxWidth: The maximum width of the output stamp.
  • MaxHeight: The maximum height of the output stamp.
  • MinWidth: The minimum width of the output stamp.
  • MinHeight: The minimum height of the output stamp.
  • Hyperlink: Makes stamped elements of this Stamper have an on-click hyperlink. Note: HTML links created by link(a) tags are not reserved by stamping.
  • Scale: Applies a percentage scale to the stamps to make them larger or smaller. The default is 100 (Percent), which has no effect.
  • IsStampBehindContent: Set to true to apply the Stamp behind the content. If the content is opaque, the Stamp may be invisible.
  • WaitFor: A convenient wrapper to wait for various events or some time.
  • Timeout: Render timeout in seconds. The default value is 60.

IronPDF's stamper options provide advanced customization, allowing users to enhance PDFs with transparency, precise rotation, and controlled dimensions. Features like Hyperlink and Scale facilitate the incorporation of all the interactive elements, adhering to file specifications and emphasizing only the content. The IsStampBehindContent option strategically positions stamps, ensuring they are part of the same object, not the fields. At the same time, the WaitFor feature efficiently manages rendering events, making IronPDF a versatile tool for PDF customization, including original page rotation.

Conclusion

In conclusion, IronPDF's stamper functionality provides a versatile and user-friendly solution for enhancing PDF documents. Whether adding simple text labels, incorporating images, or leveraging the power of HTML and CSS with the HTMLStamper, IronPDF caters to a wide range of customization needs.

The ease of use and practical examples showcasing the application of text and image stamps make it accessible for users with varying technical expertise. The stamper options, including opacity, rotation, and scale, contribute to a comprehensive toolkit for users seeking to customize PDFs effortlessly. IronPDF's stamper feature stands out as a reliable and efficient tool, empowering users to easily elevate their PDF documents.

Essentially, IronPDF effortlessly elevates PDFs for both basic and advanced needs. For inquiries or feature requests, our support team is ready to assist.