@Connie_McLennan Thanks for linking that thread, just the kind of thing I was looking for. You don't actually have to join to look at the site- that is just a pop-up, you can close it and continue browsing. I do find it annoying, but almost all sites have something like that these days.
@purplehaze I took a look at your gallery, beautiful paintings! That sounds pretty positive. The website says 30% commission plus VAT from what I can see, maybe it's changed recently... Seeing as there's no listing cost, though, I may as well apply and see if they like me or not. Nothing to lose!
Thanks again for replying!