How can I add a full background to an A4-sized Word document?

I'm trying to add a background to an A4-sized Word document.

What is the correct background image size (in terms of resolution) to put into an A4 document? I tried Watermark, Fill effects, and tried to put the image into the header as well.

The image doesn't fit correctly – it will be centered and I need to scale it without causing a quality drop.

Solution 1:

I have had to this a couple of times for a background you don't want noobs messing with.

795 x 1123 jpg worked for me on A4 in word. When using Fill ->picture function.

Solution 2:

Page Layout > Page Color > Fill Effects > Picture > Select Picture.

Use Paint.NET, create image of 210x297mm with 200+dpi resolution and use this image as background. This should work.

Tested with Word 2007.

Solution 3:

The solution is very simple! Create a4 background image. Open word doc. Go in page setup and set footer, header and all margins values as 0 (zero). Than follow the procedure for insert background image, and image will be calibrated