Hi. Often, when I am a tour guide at the Museum of Glass, Tacoma,WA. glassblowing shop. I get a question for which I don't have a definitive answer. I thought someone might know What is special about glass that enables it to be formed by blowing? Which forces are the major factors in holding the bubble together and allows it to be deformed in an inelastically. How is it different from other materials wax, steel, ceramics, wood, etc which do not have this ability? with respect to the blowing phenomena.