Excel 2010 does not provide a native function to insert watermark unlike in Word.
Word by default has a function on the Ribbon tab to insert a watermark.
In Excel watermark can be done also using this method below.
On the Ribbon tab click on “Insert”, then click on “Header & Footer”.
On the small rectangle that will pop up after clicking “Header & Footer” type:
Type exactly as it shown “&[Picture]”, when done typing click outside the small rectangle.
Then an insert dialog box will appear choose from your PC any pictures you want as a watermark background.
Please images below on how to insert a watermark background in “Excel 2010”.
After selecting a picture to insert then the final result would be something like this:
Image inserted as watermark:
Screen shot of excel with the watermark background:
Cheers.. hope it helps!!