I'd like one that looks like this, with no knots in it (this one is sold out)
www.asos.com/asos-design/asos-design-wide-jersey-headband-in-black/prd/10134529?clr=black
It mustn't be too firm, so I can still wear it comfortably when I have a headache.
Also considering one of the plainer Seasalt Handybands but would prefer a plain colour. Are they quite soft and don't exert much pressure on the head, the way the heavily elasticated ones do?
There are obviously hundreds of headbands on Amazon and Ebay but it's hard to know what you will end up with there.
I had one in about 1991 from Boots that would have been perfect but of course that is long gone!