The scene in Spider Man 3 called for the heroine, Mary Jane, to again be in peril at the bottom of a giant spider web 40 stories in the air with cinder blocks from a nearby crumbling building falling dangerously close to her. Of course, real cinder blocks were out of the question in shooting the scene, so an effects answer was sought for just this scene. Gothic Prop Fabricators have made dozens of these blocks out of Smooth-On's FlexFoam-iT!® X 10 lb. flexible foam before for movies and commercials, too many to mention.
The below sequence shows how Gothic Props molded and cast these incredibly realistic blocks using Smooth-On's Mold Max® 30 silicone mold rubber and FlexFoam-iT!® X 10 lb. flexible foam.