I'm not sure how the granite backsplash relates to this, other than the fact that it could cover 1 1/4 " of the seam, if the backsplash is left at standard thickness. A seam will not be invisible, but a lot of it depends on the color of the stone and the skill level of the fabricator. Natural daylight shows a seam more, so if there is a window you will be more likely to see the seam. When it is done well, it is visible but not noticeable. Your eye can be tricked to not see it, so long as the color/pattern blends well.