A typically single-colored background formed into a square grid by a series of thin lines.
The lines must be perpindicular or parallel with respect to each other, but need not be with respect to the sides of the image; a square grid rotated by an angle is still a square grid.
Not to be confused with checkered background, where squares are filled with two alternating colors, or border, a line that runs along three to four edges of the image.
The following tags are aliased to this tag: tile_background (learn more).