A watermark can be inserted in Writer
document only while
Answers
Explanation:
Insert a watermark
An easy way to insert a watermark is to go to Insert tab > Watermark. It includes Custom Watermark and Preset Watermark. You can choose one of the Watermarks in Preset. <div style="margin: 20px;"class="text-center" > 
Step 1. A second way is to go to Insert > Watermark > Insert Watermark. Then It will pop up a dialog box like the following.
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Step 2. You can choose Picture watermark, or Text watermark, or both.
In Picture watermark part, browse and open an image file from your computer as your watermark. And you can set Zoom Format, Horizontal, Vertical.
In Text Watermark part you can set the Content, Font, Size, Color, Format, Horizontal, Vertical, Transparency.
Writer will automatically apply the watermark to each page except a designed page.