There are at least 2 types, Don. The older type were made from about
1910 through the 1940's. They used a die-cut paper inlay. The design
showed through and was the same color & texture as the clay on the rim.

The newer type that John was referring to is a one-piece linen disc w/
the design lithographed onto the disc. You will see a cross-hatched
pattern throughout the surface. The discs are laminated onto both sides
of the clay chip. No clay will be seen on the chip surface, only on
the edge.