Here is the basic model, before the dry powder is added. The effect of having the foam middle dome upwards is created by positioning a small object like the lid of a small jar under the middle of the foam and then pressing the whole model down onto the object. For the opposite effect, start with the foam domed up, spread the powder over the dome, then pick the model up off of the underlying object so that the dome collapses back to its original state.
This page is maintained by Vince Cronin, so send him an email if there are any problems: Vince_Cronin@baylor.edu