watermark.setVerticalAlignment(VerticalAlignment.CENTER);
watermark.setHorizontalAlignment(HorizontalAlignment.CENTER);
// Create a new paragraph and append the watermark to this paragraph.
Paragraph watermarkPara = new Paragraph(doc);
watermarkPara.appendChild(watermark);
// Insert the watermark into all headers of each document section.
for (Section sect : doc.getSections())
{
// There could be up to three different headers in each section, since we want