Quikcrete mixed with straight Acrylic Fortifier (no water) applied in several layers over a carved foam background was the method Johnny described to me when I grilled him about vivarium construction techniques in this thread:

http://www.frogforum.net/vivarium-te...ng-im-new.html

and my results:

http://www.frogforum.net/vivarium-te...-enclosed.html