Underglaze or glaze test plates are a great way to create a visual reference for your underglazes or glazes. This plate design has 24 scallops on the edges which makes it perfect for testing out 24 different colors.
I first saw test plates like these at the Sevres Ceramic factory in France. They have used this style of plate for centuries to test out glazes, underglazes, overglaze enamels (china paints) and lusters.
These plates are designed to hang on a wall so that you can quickly see examples of all of your underglazes/glazes.

Materials:
Scalloped Slab plate, bisque fired
24 underglazes or glazes
Underglaze Pencil
Brush, I am using a flat ½” and ¾ rounded flat brush
Clear glaze without zinc for underglazes