These metal brooch trays are great for showcasing your tiny felted pictures. This one is portrait format 30mm wide by 40mm high and silver in colour.
 
I recommend using a piece of felt fabric, cut to the size of the tray, to felt into. Once your felted creation is done you can stick it into the tray using PVA or crafting glue. I also recommend mixing a small amount of Modpodge or PVA glue with some water and painting it over your felted creation to stop it from pilling when worn.