Each square on a Grid is thematically and chromatically based on the squares next to it. The continuity can be dazzling. Grids can take a few hours to a few days to complete, depending on how dedicated and how quick the participants are at turning out pieces.
Some grids never reach completion.
Here you'll find the original grid projects which eventually spawned mega-projects like HyGrid and Gridcosm . Grids have been taken into three dimensions on SITO with the Cube project. The first six grids created during live SITO sessions. A 5x5 for Mondo 2000 . Never got published, but it's pretty.