Pdf pdf1 = new Pdf();
Aspose.Pdf.Section sec1 = pdf1.Sections.Add();

Text text = new Text("DO NOT COPY");
text.TextInfo.Alignment = Aspose.Pdf.AlignmentType.Center;
text.TextInfo.FontSize = 40.0f;
text.RotatingAngle = 45.0f;
text.TextInfo.Color = new Aspose.Pdf.Color("gray");

FloatingBox watermark = new FloatingBox(500, 200);
watermark.BoxVerticalPositioning = BoxVerticalPositioningType.Margin;
watermark.BoxVerticalAlignment = BoxVerticalAlignmentType.Top;
watermark.ZIndex = -1;
watermark.BoxHorizontalPositioning = BoxHorizontalPositioningType.Margin;
watermark.Paragraphs.Add(text);
pdf1.Watermarks.Add(watermark);

//setting image watermark
Aspose.Pdf.Image image1 = new Aspose.Pdf.Image();
image1.ImageInfo.File = @"d:/pdftest/Penguin.PNG";
image1.ImageInfo.ImageFileType = ImageFileType.Png;

Aspose.Pdf.FloatingBox watermark1 = new Aspose.Pdf.FloatingBox(108, 80);
watermark1.BoxHorizontalPositioning = BoxHorizontalPositioningType.Page;
watermark1.BoxHorizontalAlignment = BoxHorizontalAlignmentType.Center;
watermark1.BoxVerticalPositioning = BoxVerticalPositioningType.Page;
watermark1.BoxVerticalAlignment = BoxVerticalAlignmentType.Top;
watermark1.Padding.Top = 60;
watermark1.Paragraphs.Add(image1);
pdf1.Watermarks.Add(watermark1);
pdf1.IsWatermarkOnTop = false;

pdf1.Sections[0].Paragraphs.Add(new Text(" Aspose.Pdf is a .NET Component built to ease the job of developers to create PDF documents ranging from simple to complex on the fly programmatically. Aspose.Pdf allows developers to insert Tables, Graphs, Images, Hyperlinks and Custom Fonts etc. in the PDF documents. Moreover, it is also possible to compress PDF documents. Aspose.Pdf provides excellent security features to develop secure PDF documents. And the most distinct feature of Aspose.Pdf is that it supports the creation of PDF documents through both an API and from XML templates "));

pdf1.Save(@"d:/pdftest/Watermark_Issue.pdf");