# Watermarks > Add image and text watermarks behind the text of every page with ServerTextControl: SVG images in headers, centering, first pages, sections and removal. - **Product:** TX Text Control .NET Server - **Section:** Documentation - **Kind:** Topic - **Path:** TX Text Control .NET Server > PDF Processing > Watermarks - **3833 words** - **Web URL:** https://docs.textcontrol.com/tx-text-control-dotnet-server/pdf/watermarks/ - **LLMs URL:** https://docs.textcontrol.com/tx-text-control-dotnet-server/pdf/watermarks/llms.txt - **LLMs-Full URL:** https://docs.textcontrol.com/tx-text-control-dotnet-server/pdf/watermarks/llms-full.txt --- A "DRAFT" across every page of a contract under review, "CONFIDENTIAL" on an internal report or the name of the person who downloaded a document: watermarks mark the status or the origin of a document on each page. In TX Text Control, a watermark is an image in the header that lies behind the text. You center it on pages of any size, create text watermarks without an image file, limit them to some pages or sections and remove them again. A first watermark on a loaded PDF is added in [Add a Watermark](https://docs.textcontrol.com/tx-text-control-dotnet-server/getting-started/pdf/load-modify/#add-a-watermark) in Getting Started. Headers and images in general are described in [Headers and Footers](https://docs.textcontrol.com/tx-text-control-dotnet-server/document-processing/headers-footers/llms-full.txt) and [Images](https://docs.textcontrol.com/tx-text-control-dotnet-server/document-processing/images/llms-full.txt). ### How Watermarks Work Images, text frames, barcodes and drawings can be placed anywhere on a page while they belong to a header or footer. They're then shown in the background of every page on which the header or footer appears, and they don't change the height of the header. Three settings make an image a watermark: - **In the header.** The image is added to the [Images](https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/txtextcontrol/headerfooter/images-property/llms-full.txt) collection of a header, so it's repeated on every page of its section. - **Fixed on the page.** `ImageInsertionMode.FixedOnPage` places the image at a position on the page instead of at a text position. - **Behind the text.** `ImageInsertionMode.BelowTheText` puts the image under the text, so the text remains readable. SVG images are the best choice for watermarks: one image fits every size, and a document saved as PDF contains them as vector graphics. Each kind of header, such as the header of the first page or of even pages, has its own background. ### Center a Watermark on Every Page Documents can contain sections with different page sizes and orientations. The following program adds an SVG image to the header of every section of a document and centers it on the page of its section: ```csharp using TXTextControl; using (ServerTextControl tx = new ServerTextControl()) { tx.Create(); tx.Load("Documents/sample.docx", StreamType.WordprocessingML); // Page sizes and margins in twips, the unit of image sizes and locations tx.PageUnit = MeasuringUnit.Twips; foreach (Section section in tx.Sections) { section.HeadersAndFooters.Add(HeaderFooterType.Header); HeaderFooter header = section.HeadersAndFooters.GetItem(HeaderFooterType.Header); // 8 is the import filter for SVG Image watermark = new Image("Documents/draft.svg", 8); header.Images.Add(watermark, 1, new System.Drawing.Point(0, 0), ImageInsertionMode.FixedOnPage | ImageInsertionMode.BelowTheText); watermark.Name = "watermark"; // Center the image between the page margins SectionFormat format = section.Format; int x = (int)((format.PageSize.Width - watermark.Size.Width - format.PageMargins.Left - format.PageMargins.Right) / 2); int y = (int)((format.PageSize.Height - watermark.Size.Height - format.PageMargins.Top - format.PageMargins.Bottom) / 2); watermark.Location = new System.Drawing.Point(x, y); } tx.Save("sample-draft.pdf", StreamType.AdobePDF); } ``` The code works as follows: - [ServerTextControl.PageUnit](https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/txtextcontrol/servertextcontrol/pageunit-property/llms-full.txt) sets the unit of page sizes and margins to a `MeasuringUnit` value: `Millimeter`, `CentiInch`, `StandardWPF` or `Twips`. With `Twips`, they use the same unit as [FrameBase.Size](https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/txtextcontrol/framebase/size-property/llms-full.txt) and [FrameBase.Location](https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/txtextcontrol/framebase/location-property/llms-full.txt), 1/1440 inch. - [Section.HeadersAndFooters](https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/txtextcontrol/section/headersandfooters-property/llms-full.txt) adds a header to one section. [GetItem](https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/txtextcontrol/headerfootercollection/getitem-method/llms-full.txt) returns it. - [ImageCollection.Add](https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/txtextcontrol/imagecollection/add-method/llms-full.txt) with a page number and a location places the image at a fixed position. - The position subtracts the image size and both page margins from the page size, as the blog article [Adding Watermarks to PDF Documents in .NET C#](https://www.textcontrol.com/blog/2025/02/06/adding-watermarks-to-pdf-documents-in-net-c-sharp/) calculates it. [SectionFormat.PageSize](https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/txtextcontrol/sectionformat/pagesize-property/llms-full.txt) and [PageMargins](https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/txtextcontrol/sectionformat/pagemargins-property/llms-full.txt) provide the values of each section. - [FrameBase.Name](https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/txtextcontrol/framebase/name-property/llms-full.txt) marks the image, so your code can find and remove it later. The horizontal position is measured from the left page margin, so the calculation uses these values: ![Diagram of a page with its width, the left and right page margins, the image width and the horizontal location of the image, measured from the left margin](https://docs.textcontrol.com/assets/img/tx-text-control-dotnet-server/watermark-position.4086568e.webp) Each section gets an image object of its own. Save the result with `StreamType.AdobePDF`, or as DOCX or in the TX Text Control format to keep working on it. ### Create a Text Watermark A text watermark doesn't need an image file: your code writes an SVG image with a `text` element, rotates the text and passes the image as a stream. The following program adds a gray, rotated "CONFIDENTIAL" to the header of every section: ```csharp using System.Text; using TXTextControl; string svg = "" + "CONFIDENTIAL" + ""; byte[] data = Encoding.UTF8.GetBytes(svg); using (ServerTextControl tx = new ServerTextControl()) { tx.Create(); tx.Load("Documents/sample.docx", StreamType.WordprocessingML); foreach (Section section in tx.Sections) { section.HeadersAndFooters.Add(HeaderFooterType.Header); HeaderFooter header = section.HeadersAndFooters.GetItem(HeaderFooterType.Header); // The stream must stay open until the image has been added using (MemoryStream stream = new MemoryStream(data, 0, data.Length, false, true)) { Image watermark = new Image(stream); header.Images.Add(watermark, 1, new System.Drawing.Point(1440, 2880), ImageInsertionMode.FixedOnPage | ImageInsertionMode.BelowTheText); watermark.Name = "watermark"; } } tx.Save("sample-confidential.pdf", StreamType.AdobePDF); } ``` The code works as follows: - `text-anchor='middle'` centers the text at its `x` position, and `transform='rotate(...)'` turns it around the center of the image. The `fill` color sets how strong the watermark appears. - The `Image` constructor with a `MemoryStream` needs no filter index. The stream must be publicly visible, which the fifth argument of the `MemoryStream` constructor sets, as [Insert an Image From a Byte Array](https://docs.textcontrol.com/tx-text-control-dotnet-server/document-processing/images/#insert-an-image-from-a-byte-array) explains. - The location is given in twips, 1440 horizontally and 2880 vertically; the centering calculation of the previous section works here as well. The font of the SVG text must be available on the server, as [Make Fonts Available on the Server](https://docs.textcontrol.com/tx-text-control-dotnet-server/document-processing/creating/#make-fonts-available-on-the-server) describes. TX Text Control supports SVG 1.1 without external images and style sheets, interactivity, animation, advanced text transformations and image processing effects such as patterns, masking and filters. The blog article [Generating and Adding Watermarks to Documents using C#](https://www.textcontrol.com/blog/2023/12/20/generating-and-adding-watermarks-to-documents-using-csharp/) sizes the SVG image to the measured text. ### Limit a Watermark to Some Pages The header you add the image to decides where the watermark appears: - **The first page only.** Add the image to the header of the type `HeaderFooterType.FirstPageHeader`, the special header of the first page of the document or of a section. - **Even pages.** `HeaderFooterType.EvenHeader` adds a header for even pages, which gets its own watermark. - **One section.** Use the headers of a single section, such as `tx.Sections[2].HeadersAndFooters`, and set [ConnectedToPrevious](https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/txtextcontrol/headerfooter/connectedtoprevious-property/llms-full.txt) to `false`, so the header of that section can have content of its own. [Give a Section Its Own Header](https://docs.textcontrol.com/tx-text-control-dotnet-server/document-processing/headers-footers/#give-a-section-its-own-header) shows this. - **Selected pages.** Without a header, add the image to the main text on the pages you choose: loop through [GetPages](https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/txtextcontrol/servertextcontrol/getpages-property/llms-full.txt) and call `tx.Images.Add(image, page.Number, location, ImageInsertionMode.FixedOnPage | ImageInsertionMode.BelowTheText)` after the content of the document is final, so that the page numbers no longer change. ### Add a Watermark for Each Recipient A watermark with the name of the recipient, the download time and a document ID shows who received a copy. Add it when the document is downloaded, so that templates stay clean. Because a watermark in a PDF can be removed in an editor, combine it with metadata, an embedded file with the same data and a digital signature that makes changes detectable. The blog article [Secure by Design: Dynamic Watermarking for Enterprise Documents in C# .NET](https://www.textcontrol.com/blog/2026/02/06/secure-by-design-dynamic-watermarking-for-enterprise-documents-in-csharp-dotnet/) builds this in four steps. [Document Metadata](https://docs.textcontrol.com/tx-text-control-dotnet-server/pdf/metadata/llms-full.txt), [Attachments](https://docs.textcontrol.com/tx-text-control-dotnet-server/pdf/attachments/llms-full.txt) and [Signing PDF Documents](https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/signing/llms-full.txt) describe the parts. ### Remove a Watermark A watermark that your application added and named can be removed from documents saved as DOCX or in the TX Text Control format. The following program removes the images named "watermark" from all headers and footers: ```csharp using TXTextControl; using (ServerTextControl tx = new ServerTextControl()) { tx.Create(); tx.Load("Documents/contract-draft.docx", StreamType.WordprocessingML); foreach (IFormattedText textPart in tx.TextParts) { if (textPart is HeaderFooter header) { // null if the header has no image with this name Image watermark = header.Images.GetItem("watermark"); if (watermark != null) { header.Images.Remove(watermark); } } } tx.Save("contract-final.pdf", StreamType.AdobePDF); } ``` [ServerTextControl.TextParts](https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/txtextcontrol/servertextcontrol/textparts-property/llms-full.txt) contains the headers and footers of all sections. [ImageCollection.GetItem](https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/txtextcontrol/imagecollection/getitem-method/llms-full.txt) finds an image by its name, and [Remove](https://docs.textcontrol.com/tx-text-control-dotnet-server/reference/txtextcontrol/imagecollection/remove-method/llms-full.txt) deletes it. In the Document Viewer, users mark documents with stamps instead, which are annotations; [Add Custom Stamps](https://docs.textcontrol.com/tx-text-control-dotnet-server/document-viewer/annotations/#add-custom-stamps) describes them. ### Next Steps - [Headers and Footers](https://docs.textcontrol.com/tx-text-control-dotnet-server/document-processing/headers-footers/llms-full.txt): work with the headers that hold watermarks. - [Images](https://docs.textcontrol.com/tx-text-control-dotnet-server/document-processing/images/llms-full.txt): insert and position images. - [Signing PDF Documents](https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/signing/llms-full.txt): protect a watermarked PDF against changes. - [PDF Creation](https://docs.textcontrol.com/tx-text-control-dotnet-server/pdf/creation/llms-full.txt): control the PDF documents you save. --- ## Nearby - **Previous:** [Document Metadata](https://docs.textcontrol.com/tx-text-control-dotnet-server/pdf/metadata/llms-full.txt) - **Next:** [PDF Validation](https://docs.textcontrol.com/tx-text-control-dotnet-server/pdf/validation/llms-full.txt)