Plaster is used for many purposes. In structural geology we can use it as a deformable material in a deformation box. It requires that we mix the plaster with water and do the deformation just before it solidifies.
We have done plaster experiments in the past in Bergen (introduced by Roy Gabrielsen, now at Univ. of Oslo) and now we have started again. Some of these models are very interesting, particularly from a teaching/learning perspective (both professors and students learn from these experiments). Have a look at the first two experiments here.
The first model shows the development of a nice in-sequence imbricate structure, the second model shows the development of back-thrusts and a very nice master thrust that makes a ramp as the hanging wall overrides the footwall. Many useful details can be noted: the rotation of layers in the hanging wall and extension above the ramp are some.