Roberta Sudoku Quilt - This is the second in a series of quilts I have made based on the logic puzzle called "Sudoku". Each row and column has nine blocks, and there are also nine nine-patch blocks. In the puzzle, the numbers 1-9 are used and may not be repeated within a row, column or three by three block. I substituted 9 fabrics for the numerals of a completed puzzle. The result has a pleasing random effect, I think.