A text watermark is fully customizable: font, size, color, rotation angle (diagonal looks professional), transparency, and position. Optimal transparency for most use cases is 20–40%: the mark is visible but does not obscure the main content.
The watermark is rendered on top of page content. Removing it requires specialized tools with layer access – a regular PDF reader shows only the finished document with the mark.
If you need the watermark on specific pages only, select them: for example, only the first page or all pages except the first.