GridView pads out its delegate to ensure a uniform grid. This, however, causes items to be placed on fractional pixels, leading to blurry rendering and uneven hinting.
Instead of adjusting padding calculation to return whole pixels, which will again cause a gap at the right side of the screen, since there's 20 icons in a row, slightly shift the delegate contents to move them back to whole pixels.
Moreover, DropShadow renders the entire item with a drop shadow, so keeping the Label visible results in two labels ontop of each other leading to bolder text.

• Verified with gamma ray that the Label is now placed at integer scene coordinates
• Font rendering does look a lot nicer, especially in second and lines further down
• Verified that in software rendering Label renders fine just without a shadow
• Verified that label hides when renaming file
• Verified gap at the right of the screen is virtually unchanged