Your image is perfectly good. THe problem is that your printer is shrinking it to fit on the page. You need to either crop the image tightly so that it fits inside the margins of an A4 or letter page (go to Image->Canvas Size and pick 11x8 inches and make sure the image fits).

If you need larger images than will fit on one sheet of A4, use posterazor to cut up the image into printer friendly chunks.

Looking good! THe only price I charge for the use of these is that after you've made your tiles and used them in the game that you take a photo and post it here