There's no way to prevent the background picture from tiling.
You could add some white or grey around the picture, to frame it, and it
might be less obvious that a bit of tiling has occurred.
Zippy wrote:
When adding a picture as a background in Excel it appears to tile the
picture. I've changed the size many times, but I can't find a size that fits
the screen without some tiling showing. It's OK to tile as long as I can get
the picture to exactly fill the screen so it only shows the picture and not
part of it repeating. I hope that made sense. Thanks for your help.
--
Debra Dalgleish
Excel FAQ, Tips & Book List
http://www.contextures.com/tiptech.html