Since Excel XP it has been possible to insert a picture into a custom header or footer. Our sister site, AccountingWEB.co.uk investigated some potential uses for this facility.
Excel's View-Header/Footer menu option will take you to the Header/Footer section of the Page Setup screen. Clicking on the Custom Header or Custom Footer button presents you with three sections: Left, Center and Right. As well as typing text or using buttons to insert useful details such as page numbers, date, time and file and sheet references, Excel XP and later versions also include an Insert Picture button, and a Format Picture button to format the picture once inserted. Each of the three sections can incorporate a single picture making for a total of six pictures in all – three in the header and three in the footer.
The approach is not particularly visual – the header or footer section just displays &[Picture]. However the Format Picture dialog lets you change the size of the picture and also lets you crop it by entering measurements from each edge. In addition, the Image control allows you to change the brightness and contrast or choose one of the presets – such as Washout – which could be used if you wanted to use a picture as a watermark. Pictures can't be pasted in, but must be selected as a saved file.
In order to leave enough room for your chosen picture (unless you want it to sit behind the normal spreadsheet content as a watermark), you may need to adjust the top or bottom margins via the Page Setup screen.
In Excel 2007 the new Page Layout view (View tab, Workbook Views section, Page Layout; or Page Layout view button on the status bar) provides a much more visual approach, although with the same limitations to the picture selection and formatting process.
When in Page Layout view you simply need to click in one of the three header sections to open the Header & Footer Tools contextual tab containing all the required tools. Clicking outside that section will then immediately display the result, rather than needing you to go to Print Preview. Here we've inserted a 'Washed Out' picture in the left section as a watermark and inserted a logo in the center section: