Getting ready to take my first shot at building a tunnel/mountain. I've started rough carving the basic structure out of pink foam and need to start picking up supplies to finish. I plan to fill it out with cardboard strips, cover that with plaster cloth and then texture it with Structolite. Only problem is I can't find Structolite anywhere in Seattle. The local Home Despot has USG "UltraLightweight All Purpose" and "Lightweight All Purpose" joint compound. Are these similar and good substitutes for Structolite?
Google seattle drywall supply and you will find somewhere that has structolite or gypsolite, might even find a drywall contractor that will sell you some.