So I found a small book in a very good (if expensive) bookshop on Pall Mall called Hatchards. It’s called ‘Medieval Tiles’ - as you might have expected - and contains a large number of pictures. Not maybe in as much detail as I might like, but still.
One simple example from the beginning of the book is an Anglo-Saxon one. It looks like:
which looks nice … as a tile. Making that in a watercolour was a different matter. So I just did something vaguely similar.
I used the basic geometry, and then painted it in two different greens. One in opaque (gouache) and transparent for the outer part of each leaf.
A subtle effect, but quite nice. Perhaps the design could be improved with some more detail or other colours.
Here is the link to the finished item on Etsy