I’m in the middle of sharing a series of related designs – which started with Sunday sketch #400 and will end in another 2 weeks – and this week’s might be my favourite.

Remember that the series started with clamshells: each one was made from the quarter-circle curves of four adjacent blocks and contained a half-circle or a full circle (cut in half) in the middle.

This week’s design is much the same, with one small tweak: two of the four blocks in each clamshell have been flipped and rotated, so the inner half-circle is vertical in 2 quadrants of the clamshell and horizontal in the other two. Colouring the quarter- and half-circles differently helps to create smaller breaking waves within the larger clamshell waves.

Don’t you just love it?!

The fact that the breaking waves change direction in each row also helps to create more movement.

I chose a three-colour palette for this design, although I think you could expand the palette (but not reduce it: a two-colour palette won’t work). These versions are all a little wacky, but I created them using the ‘Randomize’ feature in Electric Quilt 8, which often comes up with some pretty interesting colour combos.

Here’s one of my fallback palettes: Kona Gotham Grey, Banana Pepper and Ballet Slipper (although the colours never look the same in real life as they do on the screen).

I like the idea of using more closely related shades too, to give the feel of a frothy, bubbly mixture of something (water, if you used blues).

I really love this design, and I’d love to see it made in fabric (speaking of which, I think it would make a great fabric design, too). I’d need to make a few blocks (probably using templates) to get comfy with the idea of double curves before committing to a full quilt. It would be a lot of repetitive piecing, but the overall effect would be cool.