Since I saw that photo I've been pondering the different possibilities, and poking at one in particular over and over when I get a few minutes in the sewing room. Obsessing and making messes are what I do best.
I'm calling it a modular cathedral window. The advantage of this approach is that you can have different colors across the block and even different colors within the modules. It doesn't require calculations or complicated folding. It's great for using up scraps. And because each quarter of the block is constructed individually, it's easily adapted to variations.
To make the base module you take three squares of the same size. Press two of them in half along the diagonal. Lay them over the other unfolded square, with the folded edges meeting along the diagonal.
I experimented with stitching along the module edges with a straight stitch and a zig zag and didn't like either approach. I also tried using a tack stitch in the corners where the edges met, but I don't even think that's necessary now. Instead, I am just using a dab of fabric glue to tack down the corners where they meet.
Rolling back the bias edge and stitching it down was easier than I expected. At first I did it as I completed each module, before stitching them together, but some of the rolls got into the seam allowances that way. So now I'm waiting to roll back the bias edges until I've stitched my modules together. I am not given to patience in the sewing room, so I'll admit that waiting to see the end result is hard. (Photo below prior to my glue and patience revelations)
The downside of the modular cathedral window is those seam allowances. Six layers of fabric coming together. The traditional cathedral window definitely has an advantage here. Press the seam allowances open and hope for the best.
I almost didn't show that last picture. I don't really know what a "good" cathedral window looks like so I'm not sure whether to be impressed or embarrassed with myself. Silliness. Not important. Just an experiment.
So what do you think, is it in your brain now too? I just want to keep playing with this so I'm thinking I'll post a new block using this technique every week or so. It won't have the structure of a full quilt along because I don't want to make all those decisions about size and yardage right now, but I can tell you: 9 inch finished blocks. Lots of five inch squares required. I'm buying a couple Kona charm squares packs to make it easy on myself, but I'll be cutting into yardage too along the way. I can't wait to show you some of the variations I'm cooking up. I'll start with the first block this week!
Single window block
Squared window block
Sweet garden block
Little spinner block
Big spinner block