Daddy's sudoku quilt

This was the only Christmas present that didn't get done on time last year. It's a lap quilt for my dad, who loves to do sudoku puzzles. In this pattern, fabric is substituted for numbers, making a sudoku grid out of colors. I lost count of how many times I checked this to make sure I hadn't twisted a block - the equivalent of screwing up a sudoku writing in pen - except I wouldn't just throw this out the way I could if I screwed up a written sudoku. I also did numbers in trapunto in the single blocks in the top and bottom borders. I was able to give it to him in person when we visited last week. He loved it, which makes me very happy.