Office 2011 for Mac: Make a Watermark in an Excel Worksheet
You can use the Picture feature of the Header/Footer toolbar in Excel 2011 for Mac to insert a picture as a watermark. In an electronic environment, you create a watermark by formatting text and pictures to appear only faintly and then putting them into the background.
A watermark gets its name from a paper-manufacturing process in which words or symbols are embedded in paper pages by wetting the paper.
Follow this step-by-step process to insert WordArt as a watermark:
A text box with placeholder text appears and the Format Ribbon displays.
Type the text that will be your watermark.
It might be something like Confidential.
Use the Ribbon to format your text to perfection.
Right-click the border of the WordArt and choose Save as Picture from the pop-up menu that appears.
The Save dialog appears.
Navigate to a handy location and click Save.
You're now done with the WordArt you created, and you can delete it if you want.
In the workbook where you want the watermark, choose View→Page Layout or click a Page Layout button.
The workbook switches to Page Layout View.
Double-click the center of the header area, where it says Double-Click to Add Header.
Click the Insert Picture button on the Header/Footer toolbar.
A Choose a Picture dialog makes its appearance.
Go to where you saved your WordArt and select the image.
Click the Insert button in the Choose a Picture dialog.
Click the Format Picture button on the Header/Footer toolbar.
On the Size and Picture tabs of the Format Picture dialog, set rotation, brightness, and other settings to make your picture a subtle watermark.
Click OK to close the Format Picture dialog and then click Close to close the Header/Footer toolbar.