Stamp Text & Image on PDFs using C# and IronPDF

What Does the Output PDF Look Like?

How Can I Create Multi-Line Text Stamps?

Use the <br> tag for multi-line text in TextStamper. For example, "line 1
line 2" produces "line 1" on the first line and "line 2" on the second line. This creates address stamps or multi-line watermarks.

What Does the Image Stamp Output Look Like?

Which Image Formats Are Supported?

ImageStamper supports PNG, JPEG, GIF, and SVG through URI references or file paths. Ensure proper network connectivity for remote images. For Azure environments, consider using images from Azure Blob Storage.

What Happens When Stamps Overlap?

Can I Mix Different Stamp Types?

ApplyMultipleStamps accepts arrays containing any stamper types. Combine TextStamper, ImageStamper, HTMLStamper, and BarcodeStamper in one operation. Create complex document layouts with headers, footers, watermarks, and identification codes simultaneously.

What Are the Key Positioning Properties?

• HorizontalAlignment: Horizontal alignment relative to the page. Default: HorizontalAlignment.Center.
• VerticalAlignment: Vertical alignment relative to the page. Default: VerticalAlignment.Middle.
• HorizontalOffset: Horizontal offset. Default: 0, unit: MeasurementUnit.Percentage. Positive values offset right, negative values offset left.
• VerticalOffset: Vertical offset. Default: 0, unit: MeasurementUnit.Percentage. Positive values offset down, negative values offset up.

How Do I Set Precise Offsets?

Specify HorizontalOffset and VerticalOffset using the Length class. Default measurement unit is percentage. Available units include inches, millimeters, centimeters, pixels, and points. This enables precise positioning like setting custom margins in PDF documents.

Code

:path=/static-assets/pdf/content-code-examples/how-to/stamp-text-image-stamp-location.cs

using IronPdf.Editing;
using System;

// 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),
};

Code

:path=/static-assets/pdf/content-code-examples/how-to/stamp-text-image-multiple-stamps.cs

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");

What Are the Essential HTML Stamper Properties?

• Html: HTML fragment to stamp onto your PDF. External references to JavaScript, CSS, and images are relative to HtmlBaseUrl.
• HtmlBaseUrl: Base URL for external CSS, JavaScript, and image file references.
• CssMediaType: Enables Media="screen" CSS styles. Setting AllowScreenCss=false renders stamps using CSS media="print". Default: PdfCssMediaType.Screen.

Why Use HTML Stamper Over Text Stamper?

HTMLStamper provides full HTML and CSS support for complex layouts, multiple fonts, colors, and embedded images in one stamp. Ideal for rich content watermarks or headers. Maintains consistent branding and works with responsive CSS designs.

Code

:path=/static-assets/pdf/content-code-examples/how-to/stamp-text-image-stamp-text.cs

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");

What Configuration Options Are Available for Barcodes?

• Value: String value of the barcode.
• BarcodeType: Encoding type supporting QRCode, Code128, and Code39. Default: QRCode.
• Width: Rendered barcode width in pixels. Default: 250px.
• Height: Rendered barcode height in pixels. Default: 250px.

When Should I Use Each Barcode Type?

QRCode handles URLs and large data sets (up to 4,296 alphanumeric characters). Code128 suits alphanumeric data with high density requirements. Code39 works for simple numeric or uppercase letter combinations. Consider scanning equipment compatibility when selecting barcode types.

How Do I Control Stamp Appearance?

• Opacity: Controls transparency. 0 is invisible, 100 is opaque.
• Rotation: Rotates stamp clockwise from 0 to 360 degrees.
• MaxWidth: Maximum width of output stamp.
• MaxHeight: Maximum height of output stamp.
• MinWidth: Minimum width of output stamp.
• MinHeight: Minimum height of output stamp.
• Hyperlink: Adds on-click hyperlink to stamped elements. Note: HTML links (a tags) aren’t preserved by stamping.
• Scale: Applies percentage scale to stamps. Default: 100 (no effect).
• IsStampBehindContent: Places stamp behind content. Stamp may be invisible if content is opaque.
• WaitFor: Waits for events or time. See using WaitFor to delay PDF render.
• Timeout: Render timeout in seconds. Default: 60.

Which Properties Are Most Commonly Used?

Opacity and IsStampBehindContent create watermarks. Scale and Rotation adjust visual positioning and sizing. Example:

// Create a semi-transparent watermark behind content
TextStamper watermark = new TextStamper()
{
    Text = "CONFIDENTIAL",
    FontSize = 60,
    FontColorCode = "#CCCCCC",
    Opacity = 25,
    Rotation = -45,
    IsStampBehindContent = true,
    VerticalAlignment = VerticalAlignment.Middle,
    HorizontalAlignment = HorizontalAlignment.Center
};

// Create a semi-transparent watermark behind content
TextStamper watermark = new TextStamper()
{
    Text = "CONFIDENTIAL",
    FontSize = 60,
    FontColorCode = "#CCCCCC",
    Opacity = 25,
    Rotation = -45,
    IsStampBehindContent = true,
    VerticalAlignment = VerticalAlignment.Middle,
    HorizontalAlignment = HorizontalAlignment.Center
};