Thanks for taking interest in GroupDocs.Watermark for Java.
Yes, GroupDocs.Watermark provides the feature of locking the watermark that can not be easily removed. Currently, locking of the watermark is not supported for Word documents, however, we have logged it in our Issue Tracking System as WATERMARKNET-893. We are investigating the possible scenarios that can be implemented to make the watermarks read-only. Following are the ways to forbid the users from removing the watermark in PDF, Excel, and PowerPoint documents.
GroupDocs.Watermark provides PDF document rasterization to protect the watermark from removal. To learn about how to rasterize a document using GroupDocs.Watermark, please visit this documentation article.
GroupDocs.Watermark allows you to lock the watermark in spreadsheet documents. CellsShapeSettings.setLocked method is used for this purpose as shown in the following code sample.
CellsDocument doc = Document.load(CellsDocument.class, "sample.xlsx");
// Add text watermark
TextWatermark textWatermark = new TextWatermark("Test watermark", new Font("Arial", 8));
CellsShapeSettings settings = new CellsShapeSettings();
// Save document
Similar to the spreadsheet documents, you can lock the watermark in PowerPoint documents using setLocked method of SlidesShapeSettings class and passing the SlidesShapeSettings object in addWatermark method.
In fact, GroupDocs.Watermark does not work to freeze the panes and columns in Excel, instead, it uses locking mechanism for the watermark objects.