These are 7×12 in. trays that is mixed media. Mixed because it has paper and acrylic paint on wood.
I found these inexpensive trays and thought I could do something with them. So I did.
I painted the outside and bottom with leftover interior paint.
I sized a piece of scrap book paper and used Mod Podge to glue it down. Then I painted the edges black. Once it was dry I could paint on it.
The possibilities are endless on these.