Pottery marks may be used by a firm to indicate a quality standard. Hypothetically a firm may use a red mark to note the pieces made with their highest quality clay, a green mark to note pieces made with the lowest quality clay.

What is the most collected item in the world?

The biggest collections in the world5: Pokémon – 17,127 items. 4: Star Wars – 93,260 items (confirmed) 3: Napkins – 125,866 items. 2: Ballpoint pens – 285,150 unique items. 1: Vinyl records – 7,000,000 plus.