I acquired this handy Windsor & Newton water color tray back in the late 70s when I was in college. I don’t do much water color work but it does come in handy now and then when I need to do some quick sketches.
It is made of tin and folds in half to make it easy to travel with. It can hold several small brushes and has a thumb hole to make it easy to hold if you want to. It is coated with durable white paint on the inside and black on the outside.