Insert watermark in the worksheet in Excel
To do it in Excel, here is the answer:
a) Click on "Header & Footer" under "Insert".
b) The display changes to "Page Layout" view automatically as shown below. The "Header & Footer Tools" tab appears. Under it, click on "Picture" with cursor in Header section, .
c) In the "Insert Picture" dialog box that comes up, navigate to the folder containing the watermark picture, select the picture and click on Insert.
d) Double click on any cell to come out of Header. Watermark picture is now added to worksheet.
Note: To come back to "Normal" view from "Page Layout" view, click on "Normal" under "View" as shown below.