So I had the idea of making my own. Using an opaque folder (of which I had a photo but can't find it now) I made this.
Apologies for the photo's I couldn't be bothered to find a space to take the photos.
I used catgut to sew it together as for some reason selotape wouldn't stick. I use another folder to cover the gap up to the photo so that reflections stop from behind the camera as well.
It seems to work quite well and only cost me £1.99. I think I may cut some of the bottom out so that I can just slot it over the beads which would make life easier.