The square is simplest patchwork form. The "One Patch," based on a grid of squares, is a quiltmaking archetype that leads into patterns of its multiples: "Four Patch,""Nine Patch," and so on. These are often the first templates learned by young girls, who occasionally return to it later in life, with a mature sense of color and a zeal for reinventing the basics. The pedestrian "One Patch," in the hands of masters like Magdalene Wilson and Polly Bennett, offers as many visual layers as any of its fancier cousins.