Light and padding, polystyrene is read as protection for something fragile in transit. Dreams of it can also point to feeling hollow, or to a cushion that is only temporary.
Does the traditional reading fit your dream, or did it mean something else to you?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.