Successful casting means that the slip should
- be cast in a short period of time (so that there is quicker wall formation against the inner surface of the mold)
- ensure the optimum cast quality of the wall (not too hard and not too soft)
- be poured out of the mold by leaving a smooth surface of inner wall (casting surface).
A good slip must
- be stable (should not get too thick after slip preparation and during casting - while the slip is in the plaster mold),
- have the highest slip density possible for a given mixture (the lowest ratio of water to dry material).
The cast pieces should
- be easily released from the mold,
- dry quickly and be crack/distortion (warpage) free,
- have enough dry strength.
In addition, the temperature of the slip and the mold should not be extreme.
