Draw multiple curved lines, add shading. Voilà! You can almost make a three dimensional image. I think this looks like folds in cloth. It’s an interesting optical illusion. The shading makes it look more rounded. It’s the first one of these I’ve done for a while. I used to draw things like this digitally on my computer, but this was drawn with metallic and matt felt pens.. I think it’s quite a good abstract image.