Bearing in mind some chemicals will set it off.
Balloon is an elastic object when filled with air it was large size due to stretching.When air is removed, the rubber sheet shrunk and so the mark with rubber stamp followed the surface reducing size.
typically it is school supplies although i have seen where diapers were included in that tax free weekend things like clothes and some school supplies, i am sure that you will find out more about it if you look it up maybe, do a search on yahoo? i am not even sure when it is this year.
