Use a picture in a header or footer to mimic a watermark
In a drawing program, such as Paintbrush, create a picture that you want to use as a watermark.
In Excel, click the worksheet that you want to display with the watermark.
NOTE Make sure that only one worksheet is selected.
On the Insert tab, in the Text group, click Header & Footer.
Excel Ribbon Image
Under Header, click either the left, center, or right header selection box.
On the Design tab of the Header & Footer Tools, in the Header & Footer elements group, click Picture Button image and then find the picture that you want to insert.
Excel Ribbon Image
Double-click the picture to insert it in the header section box.
To resize or scale the picture, click Format Picture Button image in the Header & Footer elements group, and then, in the Format Picture dialog box, select the options that you want on the Size tab.
NOTES
Changes to the picture or picture format take effect immediately and cannot be undone.
If you want to add blank space above or below a picture, in the header selection box that contains the picture, click before or after &[Picture], and then press ENTER to start a new line.
To replace a picture, select &[Picture], click Picture Button image, and then click Replace.
Before printing, make sure that the header or footer margin has sufficient space for the custom header or footer.
To delete a picture, select &[Picture] and then press DELETE.
To switch from Page Layout view to Normal view, select any cell, click the View tab, and then, in the Workbook Views group, click Normal.