Philistine! Bridget Riley is an artist who made geometric abstract art, and I saw one of her works (or the sketch of one) that I saw online. It looked a little like pleated cloth, with long wavy vertical lines and short zig-zag lines connecting them. I copied the basic idea in black and white, and the result was:
The pencil is a charcoal pencil, which gives nice broken lines. It was very fun to draw, but did not quite look as neat or fluid as the original - perhaps not surprisingly - so I thought : why not colour?
To vary the colour, I used watercolour pencil in alternating green and blue. Then varnish, then acrylic on top to unify.
Which does look nicer. Not maybe as good as I hoped, but maybe better than I deserve. Reminds me of beta-pleated sheet for some reason.