Take the image you want to make into a tile. Select 'all' and copy (but don't paste yet!) While it's selected, grab the image and push it off to the side about halfway. Now you've got only half an image. NOW* paste the image back in. Leaving it selected, push it off the side the other way. ... Now you've got an ugly seam up the middle, *but the right and left will seam perfectly*. ... Select 'all', copy it, push your image *up* this time, paste it in again and push it down. ...