Bisque is very much like ceramic, One can be told from the other by looking inside the doll (the head is usually hollow). Bisque is white with a painted exterior; ceramic is a solid color throughout.
Ceramic is kiln-fired clay. It can be distinguished from bisque by checking the inside of the doll. Ceramic will be a solid color all the way through, usually light tan, while bisque will be white inside with a painted exterior.
Composition is wood pulp in a fixative.
Crazing is a web-like network of fine cracks that appears on the surface of wood and composition dolls. It's usually caused by humidity, but can also happen when heat and cold make the doll expand and contract.
- Invisible Repair
An invisible repair is the preferred way of fixing cracks in a bisque doll. The crack is drilled out, glued, sanded, and repainted to match the surrounding surface. On composition dolls, it is when just the site of the craze is repaired and airbrushed to match the surrounding area.
Lifting happens to composition dolls when a section of wood pulp starts to separate from the rest of the doll, leaving a deep fissure. This is also caused by humidity.