Serendipity 5

I made this pattern by accident while preparing an image for an A2-sized print.

I was trying to create a Bird Wing, but I must have mistyped a parameter. (I suspect it was the tine spacing of the wavy lines.) I thought the result was worth keeping.

The pattern shown below is actually composed of four copies that tile seamlessly. If you look carefully, you can see that the top-left, top-right, bottom-left and bottom-right quadrants are identical.